Published in J Virol on June 01, 1990
Incorporation of Vpr into human immunodeficiency virus type 1 virions: requirement for the p6 region of gag and mutational analysis. J Virol (1993) 5.30
The human immunodeficiency virus type 1 vpr gene arrests infected T cells in the G2 + M phase of the cell cycle. J Virol (1995) 4.42
The human immunodeficiency virus type 1 vpr gene prevents cell proliferation during chronic infection. J Virol (1995) 4.19
Human immunodeficiency virus type 1 viral protein R localization in infected cells and virions. J Virol (1993) 4.16
Progression to AIDS in the absence of a gene for vpr or vpx. J Virol (1995) 3.96
Human immunodeficiency virus type 1 Vpr arrests the cell cycle in G2 by inhibiting the activation of p34cdc2-cyclin B. J Virol (1995) 3.69
Mechanism of action of regulatory proteins encoded by complex retroviruses. Microbiol Rev (1992) 3.60
Importance of vpr for infection of rhesus monkeys with simian immunodeficiency virus. J Virol (1993) 3.37
Evolution of the primate lentiviruses: evidence from vpx and vpr. EMBO J (1992) 3.25
The human immunodeficiency virus type 1 Vif protein modulates the postpenetration stability of viral nucleoprotein complexes. J Virol (1996) 3.22
Mutational analysis of cell cycle arrest, nuclear localization and virion packaging of human immunodeficiency virus type 1 Vpr. J Virol (1995) 2.88
Primate lentiviral Vpx commandeers DDB1 to counteract a macrophage restriction. PLoS Pathog (2008) 2.72
Highly purified human immunodeficiency virus type 1 reveals a virtual absence of Vif in virions. J Virol (1999) 2.66
The p6gag domain of human immunodeficiency virus type 1 is sufficient for the incorporation of Vpr into heterologous viral particles. J Virol (1995) 2.64
Dual regulation of silent and productive infection in monocytes by distinct human immunodeficiency virus type 1 determinants. J Virol (1992) 2.62
Rev activates expression of the human immunodeficiency virus type 1 vif and vpr gene products. J Virol (1991) 2.62
Open reading frame vpr of simian immunodeficiency virus encodes a virion-associated protein. J Virol (1990) 2.60
Vpr-induced cell cycle arrest is conserved among primate lentiviruses. J Virol (1996) 2.33
Requirement of the Pr55gag precursor for incorporation of the Vpr product into human immunodeficiency virus type 1 viral particles. J Virol (1994) 2.20
Human immunodeficiency virus type 1 Vpr induces the degradation of the UNG and SMUG uracil-DNA glycosylases. J Virol (2005) 2.17
Human immunodeficiency virus type 1 Vif protein is packaged into the nucleoprotein complex through an interaction with viral genomic RNA. J Virol (2001) 2.16
The membrane-proximal intracytoplasmic tyrosine residue of HIV-1 envelope glycoprotein is critical for basolateral targeting of viral budding in MDCK cells. EMBO J (1997) 2.10
Mutagenic analysis of human immunodeficiency virus type 1 Vpr: role of a predicted N-terminal alpha-helical structure in Vpr nuclear localization and virion incorporation. J Virol (1995) 2.09
Expression of the human immunodeficiency virus type 1 (HIV-1) nef gene during HIV-1 production increases progeny particle infectivity independently of gp160 or viral entry. J Virol (1995) 2.08
Serum Vpr regulates productive infection and latency of human immunodeficiency virus type 1. Proc Natl Acad Sci U S A (1994) 2.00
Molecular pathways in virus-induced cytokine production. Microbiol Mol Biol Rev (2001) 1.97
Vpr stimulates viral expression and induces cell killing in human immunodeficiency virus type 1-infected dividing Jurkat T cells. J Virol (1998) 1.97
A leucine triplet repeat sequence (LXX)4 in p6gag is important for Vpr incorporation into human immunodeficiency virus type 1 particles. J Virol (1995) 1.93
Human immunodeficiency virus type 1 Vpr protein binds to the uracil DNA glycosylase DNA repair enzyme. J Virol (1996) 1.84
Localization of the Vpx packaging signal within the C terminus of the human immunodeficiency virus type 2 Gag precursor protein. J Virol (1994) 1.81
Replication and pathogenicity of human immunodeficiency virus type 1 accessory gene mutants in SCID-hu mice. J Virol (1996) 1.80
Interaction with the p6 domain of the gag precursor mediates incorporation into virions of Vpr and Vpx proteins from primate lentiviruses. J Virol (1999) 1.79
The interaction of vpr with uracil DNA glycosylase modulates the human immunodeficiency virus type 1 In vivo mutation rate. J Virol (2000) 1.79
Targeting foreign proteins to human immunodeficiency virus particles via fusion with Vpr and Vpx. J Virol (1995) 1.77
Limelight on two HIV/SIV accessory proteins in macrophage infection: is Vpx overshadowing Vpr? Retrovirology (2010) 1.76
Extracellular Vpr protein increases cellular permissiveness to human immunodeficiency virus replication and reactivates virus from latency. J Virol (1995) 1.74
Interaction of the human immunodeficiency virus type 1 Vpr protein with the nuclear pore complex. J Virol (1998) 1.70
Fate of the human immunodeficiency virus type 1 provirus in infected cells: a role for vpr. J Virol (1995) 1.69
The Vpr protein from HIV-1: distinct roles along the viral life cycle. Retrovirology (2005) 1.67
CCR5 signal transduction in macrophages by human immunodeficiency virus and simian immunodeficiency virus envelopes. J Virol (2000) 1.66
Nuclear import, virion incorporation, and cell cycle arrest/differentiation are mediated by distinct functional domains of human immunodeficiency virus type 1 Vpr. J Virol (1997) 1.65
Genetic evidence that the Tat proteins of human immunodeficiency virus types 1 and 2 can multimerize in the eukaryotic cell nucleus. J Virol (1993) 1.62
Polarized human immunodeficiency virus budding in lymphocytes involves a tyrosine-based signal and favors cell-to-cell viral transmission. J Virol (1999) 1.61
A conserved dileucine-containing motif in p6(gag) governs the particle association of Vpx and Vpr of simian immunodeficiency viruses SIV(mac) and SIV(agm). J Virol (1999) 1.60
Human immunodeficiency virus type 1 Vpr protein is incorporated into the virion in significantly smaller amounts than gag and is phosphorylated in infected cells. J Virol (2000) 1.54
The glucocorticoid receptor type II complex is a target of the HIV-1 vpr gene product. Proc Natl Acad Sci U S A (1995) 1.53
Lentiviral delivery of HIV-1 Vpr protein induces apoptosis in transformed cells. Proc Natl Acad Sci U S A (1999) 1.52
Defective accessory genes in a human immunodeficiency virus type 1-infected long-term survivor lacking recoverable virus. J Virol (1995) 1.50
The double-stranded RNA-binding protein Staufen is incorporated in human immunodeficiency virus type 1: evidence for a role in genomic RNA encapsidation. J Virol (2000) 1.50
Characterization of HIV-1 vpr nuclear import: analysis of signals and pathways. J Cell Biol (1998) 1.50
A conserved LXXLF sequence is the major determinant in p6gag required for the incorporation of human immunodeficiency virus type 1 Vpr. J Virol (1996) 1.47
HIV-1 Vpr enhances viral burden by facilitating infection of tissue macrophages but not nondividing CD4+ T cells. J Exp Med (2001) 1.45
Molecular biology of the human immunodeficiency virus accessory proteins. J Virol (1994) 1.44
Vpr protein of human immunodeficiency virus type 1 forms cation-selective channels in planar lipid bilayers. Proc Natl Acad Sci U S A (1996) 1.44
A domain of human immunodeficiency virus type 1 Vpr containing repeated H(S/F)RIG amino acid motifs causes cell growth arrest and structural defects. Proc Natl Acad Sci U S A (1995) 1.43
Cell cycle- and Vpr-mediated regulation of human immunodeficiency virus type 1 expression in primary and transformed T-cell lines. J Virol (1999) 1.39
Human immunodeficiency virus type 1 (HIV-1) Vpr functions as an immediate-early protein during HIV-1 infection. J Virol (1999) 1.37
Human immunodeficiency virus type 1 Vpr interacts with HHR23A, a cellular protein implicated in nucleotide excision DNA repair. J Virol (1997) 1.37
Vpx of simian immunodeficiency virus is localized primarily outside the virus core in mature virions. J Virol (1993) 1.36
Activation of the ATR pathway by human immunodeficiency virus type 1 Vpr involves its direct binding to chromatin in vivo. J Virol (2005) 1.34
Human immunodeficiency virus type 1 (HIV-1) Vpr enhances expression from unintegrated HIV-1 DNA. J Virol (2003) 1.31
The HIV-1 vpr protein acts as a negative regulator of apoptosis in a human lymphoblastoid T cell line: possible implications for the pathogenesis of AIDS. J Exp Med (1998) 1.30
Nucleocytoplasmic shuttling by human immunodeficiency virus type 1 Vpr. J Virol (2001) 1.27
Localization of HIV-1 Vpr to the nuclear envelope: impact on Vpr functions and virus replication in macrophages. Retrovirology (2007) 1.27
Molecular biology and pathogenesis of animal lentivirus infections. Clin Microbiol Rev (1996) 1.26
Human immunodeficiency virus type 1 Vpr impairs dendritic cell maturation and T-cell activation: implications for viral immune escape. J Virol (2005) 1.25
Effect of human immunodeficiency virus type 1 protein R (vpr) gene expression on basic cellular function of fission yeast Schizosaccharomyces pombe. J Virol (1996) 1.24
Mutagenesis of the putative alpha-helical domain of the Vpr protein of human immunodeficiency virus type 1: effect on stability and virion incorporation. Proc Natl Acad Sci U S A (1995) 1.24
Comparison of cell cycle arrest, transactivation, and apoptosis induced by the simian immunodeficiency virus SIVagm and human immunodeficiency virus type 1 vpr genes. J Virol (2001) 1.21
HIV-1 accessory protein Vpr: relevance in the pathogenesis of HIV and potential for therapeutic intervention. Retrovirology (2011) 1.17
Regulation of HIV-1 transcription in cells of the monocyte-macrophage lineage. Retrovirology (2009) 1.17
A virion-specific inhibitory molecule with therapeutic potential for human immunodeficiency virus type 1. Proc Natl Acad Sci U S A (1993) 1.13
Vpr and Vpu are important for efficient human immunodeficiency virus type 1 replication and CD4+ T-cell depletion in human lymphoid tissue ex vivo. J Virol (2004) 1.12
Influence of reverse transcriptase variants, drugs, and Vpr on human immunodeficiency virus type 1 mutant frequencies. J Virol (2003) 1.09
Human immunodeficiency virus type 1 Vpr-dependent cell cycle arrest through a mitogen-activated protein kinase signal transduction pathway. J Virol (2005) 1.08
Extracellular HIV-1 virus protein R causes a large inward current and cell death in cultured hippocampal neurons: implications for AIDS pathology. Proc Natl Acad Sci U S A (1998) 1.08
Analysis of the transcription pattern and mapping of the putative rev and env splice junctions of bovine immunodeficiency-like virus. J Virol (1991) 1.08
HIV-1 Vpr-a still "enigmatic multitasker". Front Microbiol (2014) 1.07
Maedi-visna virus and caprine arthritis encephalitis virus genomes encode a Vpr-like but no Tat protein. J Virol (2003) 1.06
Context-dependent role of human immunodeficiency virus type 1 auxiliary genes in the establishment of chronic virus producers. J Virol (1993) 1.06
Phosphorylation of human immunodeficiency virus type 1 Vpr regulates cell cycle arrest. J Virol (2000) 1.05
Virus-producing cells determine the host protein profiles of HIV-1 virion cores. Retrovirology (2012) 1.04
A carboxy-terminally truncated form of the human immunodeficiency virus type 1 Vpr protein induces apoptosis via G(1) cell cycle arrest. J Virol (2000) 1.01
Nuclear export of Vpr is required for efficient replication of human immunodeficiency virus type 1 in tissue macrophages. J Virol (2003) 1.00
Inhibition of human and simian immunodeficiency virus protease function by targeting Vpx-protease-mutant fusion protein into viral particles. J Virol (1996) 0.96
HIV-1 Vpr induces defects in mitosis, cytokinesis, nuclear structure, and centrosomes. Mol Biol Cell (2004) 0.96
Human immunodeficiency virus type 1 infection of the brain. Clin Microbiol Rev (1993) 0.94
Human immunodeficiency virus viral protein R as an extracellular protein in neuropathogenesis. Adv Virus Res (2011) 0.94
Development of HIV reservoir targeted long acting nanoformulated antiretroviral therapies. Curr Med Chem (2014) 0.94
The functions of the HIV1 protein Vpr and its action through the DCAF1.DDB1.Cullin4 ubiquitin ligase. Cytokine (2010) 0.93
Development of a novel anti-HIV-1 agent from within: effect of chimeric Vpr-containing protease cleavage site residues on virus replication. Proc Natl Acad Sci U S A (1997) 0.92
Maintenance of an intact human immunodeficiency virus type 1 vpr gene following mother-to-infant transmission. J Virol (1998) 0.92
Human immunodeficiency virus type 1 Vpr contains two leucine-rich helices that mediate glucocorticoid receptor coactivation independently of its effects on G(2) cell cycle arrest. J Virol (2000) 0.91
Functional role of residues corresponding to helical domain II (amino acids 35 to 46) of human immunodeficiency virus type 1 Vpr. J Virol (2000) 0.90
Human immunodeficiency virus type 1 Vpr: oligomerization is an essential feature for its incorporation into virus particles. Virol J (2010) 0.89
Virion-targeted viral inactivation of human immunodeficiency virus type 1 by using Vpr fusion proteins. J Virol (1998) 0.88
Identification of the 15FRFG domain in HIV-1 Gag p6 essential for Vpr packaging into the virion. Retrovirology (2004) 0.88
Isolation of a T-lymphotropic retrovirus from a patient at risk for acquired immune deficiency syndrome (AIDS). Science (1983) 43.61
Complete nucleotide sequence of the AIDS virus, HTLV-III. Nature (1985) 30.62
Nucleotide sequence of the AIDS virus, LAV. Cell (1985) 16.81
Characterization of ribosomal frameshifting in HIV-1 gag-pol expression. Nature (1988) 10.69
Trans-acting transcriptional activation of the long terminal repeat of human T lymphotropic viruses in infected cells. Science (1984) 9.14
Functional role of human immunodeficiency virus type 1 vpu. Proc Natl Acad Sci U S A (1989) 5.72
Characterization of the reverse transcriptase from a new retrovirus (HTLV) produced by a human cutaneous T-cell lymphoma cell line. Virology (1981) 4.68
Identification of HIV-1 vpr product and function. J Acquir Immune Defic Syndr (1990) 4.35
Mutational analysis of the human immunodeficiency virus vpr open reading frame. J Virol (1989) 3.48
Replication and pathogenesis of the AIDS virus. J Acquir Immune Defic Syndr (1988) 2.50
A naturally immunogenic virion-associated protein specific for HIV-2 and SIV. Nature (1988) 2.33
A tripartite HIV-1 tat-env-rev fusion protein. EMBO J (1990) 2.01
Role of capsid precursor processing and myristoylation in morphogenesis and infectivity of human immunodeficiency virus type 1. Proc Natl Acad Sci U S A (1989) 12.54
The antigenic structure of the HIV gp120 envelope glycoprotein. Nature (1998) 12.44
The location of cis-acting regulatory sequences in the human T cell lymphotropic virus type III (HTLV-III/LAV) long terminal repeat. Cell (1985) 11.28
The trans-activator gene of the human T cell lymphotropic virus type III is required for replication. Cell (1986) 10.76
Role of the HTLV-III/LAV envelope in syncytium formation and cytopathicity. Nature (1986) 10.62
Effect of mutations affecting the p6 gag protein on human immunodeficiency virus particle release. Proc Natl Acad Sci U S A (1991) 10.05
Trans-acting transcriptional activation of the long terminal repeat of human T lymphotropic viruses in infected cells. Science (1984) 9.14
Mutation of a mutL homolog in hereditary colon cancer. Science (1994) 9.04
Major glycoprotein antigens that induce antibodies in AIDS patients are encoded by HTLV-III. Science (1985) 8.53
Rous sarcoma virus genome is terminally redundant: the 5' sequence. Proc Natl Acad Sci U S A (1977) 7.09
Trans-acting transcriptional regulation of human T-cell leukemia virus type III long terminal repeat. Science (1985) 6.51
Mutations of two PMS homologues in hereditary nonpolyposis colon cancer. Nature (1994) 6.21
Role of vif in replication of human immunodeficiency virus type 1 in CD4+ T lymphocytes. J Virol (1992) 5.85
Functional role of human immunodeficiency virus type 1 vpu. Proc Natl Acad Sci U S A (1989) 5.72
Determination of viral proteins present in the human immunodeficiency virus type 1 preintegration complex. J Virol (1991) 5.49
Intragenic cis-acting art gene-responsive sequences of the human immunodeficiency virus. Proc Natl Acad Sci U S A (1988) 5.47
Post-transcriptional regulation accounts for the trans-activation of the human T-lymphotropic virus type III. Nature (1986) 5.24
Determination of the leukaemogenicity of a murine retrovirus by sequences within the long terminal repeat. Nature (1984) 4.90
Ordered transcription of RNA tumor virus genomes. J Mol Biol (1976) 4.78
Integration of human immunodeficiency virus type 1 DNA in vitro. Proc Natl Acad Sci U S A (1990) 4.75
Effects of mutations within the 3' orf open reading frame region of human T-cell lymphotropic virus type III (HTLV-III/LAV) on replication and cytopathogenicity. J Virol (1986) 4.48
Identification of HIV-1 vpr product and function. J Acquir Immune Defic Syndr (1990) 4.35
Tissue-specific transcription preference as a determinant of cell tropism and leukaemogenic potential of murine retroviruses. Nature (1984) 4.30
Role of the matrix protein in the virion association of the human immunodeficiency virus type 1 envelope glycoprotein. J Virol (1994) 4.28
Mapping of functionally important residues of a cysteine-histidine box in the human immunodeficiency virus type 1 nucleocapsid protein. J Virol (1993) 4.22
Identification of a protein encoded by the vpu gene of HIV-1. Nature (1988) 4.05
MSI and MSII made on ribosome in idling step of protein synthesis. Nature (1972) 3.89
Herpes simplex virus type-1 can reactivate transcription of latent human immunodeficiency virus. Nature (1987) 3.77
UV-induced mutation hotspots occur at DNA damage hotspots. Nature (1982) 3.63
Vpu protein of human immunodeficiency virus type 1 enhances the release of capsids produced by gag gene constructs of widely divergent retroviruses. Proc Natl Acad Sci U S A (1993) 3.63
Structural and functional characterization of human immunodeficiency virus tat protein. J Virol (1989) 3.57
Synthesis of guanosine tetra- and pentaphosphate requires the presence of a codon-specific, uncharged transfer ribonucleic acid in the acceptor site of ribosomes. Proc Natl Acad Sci U S A (1973) 3.52
Sequence specific cleavage of DNA by the antitumor antibiotics neocarzinostatin and bleomycin. Proc Natl Acad Sci U S A (1978) 3.43
Antigens encoded by the 3'-terminal region of human T-cell leukemia virus: evidence for a functional gene. Science (1984) 3.20
Low-molecular-weight RNAs of Moloney murine leukemia virus: identification of the primer for RNA-directed DNA synthesis. J Virol (1977) 2.99
Specific binding of tryptophan transfer RNA to avian myeloblastosis virus RNA-dependent DNA polymerase (reverse transcriptase). Proc Natl Acad Sci U S A (1975) 2.97
Cis-acting sequences responsive to the rev gene product of the human immunodeficiency virus. J Acquir Immune Defic Syndr (1988) 2.97
Distribution of UV light-induced damage in a defined sequence of human DNA: detection of alkaline-sensitive lesions at pyrimidine nucleoside-cytidine sequences. Proc Natl Acad Sci U S A (1981) 2.92
HIV/HTLV gene nomenclature. Nature (1988) 2.72
Cleavage of pyrimidine dimers in specific DNA sequences by a pyrimidine dimer DNA-glycosylase of M. luteus. Nature (1980) 2.72
Structure of the genome of Moloney murine leukemia virus: a terminally redundant sequence. Cell (1978) 2.68
Activation of human immunodeficiency virus by herpesvirus infection: identification of a region within the long terminal repeat that responds to a trans-acting factor encoded by herpes simplex virus 1. Proc Natl Acad Sci U S A (1987) 2.66
Subcellular localization of the human immunodeficiency virus trans-acting art gene product. J Virol (1988) 2.64
Transformation to continuous growth of primary human T lymphocytes by human T-cell leukemia virus type I X-region genes transduced by a Herpesvirus saimiri vector. Proc Natl Acad Sci U S A (1989) 2.64
Construction of recombinant murine retroviruses that express the human T-cell leukemia virus type II and human T-cell lymphotropic virus type III trans activator genes. J Virol (1986) 2.50
Sites and structure of gamma radiation-induced DNA strand breaks. J Biol Chem (1982) 2.47
gamma Ray induced deoxyribonucleic acid strand breaks. 3' Glycolate termini. J Biol Chem (1983) 2.41
A micromethod for detailed characterization of high molecular weight RNA. Methods Enzymol (1980) 2.36
Structure of 3' terminal region of type II human T lymphotropic virus: evidence for new coding region. Science (1984) 2.32
Tissue selectivity of murine leukemia virus infection is determined by long terminal repeat sequences. J Virol (1985) 2.29
Genetic analysis of the human immunodeficiency virus type 1 integrase protein. J Virol (1994) 2.26
Location of cis-acting regulatory sequences in the human T-cell leukemia virus type I long terminal repeat. Proc Natl Acad Sci U S A (1985) 2.25
Replication of human immunodeficiency virus type 1 in primary dendritic cell cultures. Proc Natl Acad Sci U S A (1991) 2.25
Subcellular localization of the product of the long open reading frame of human T-cell leukemia virus type I. Science (1985) 2.25
Inhibition of human immunodeficiency virus syncytium formation and virus replication by castanospermine. Proc Natl Acad Sci U S A (1987) 2.25
Persistent infection of macaques with simian-human immunodeficiency viruses. J Virol (1995) 2.22
Role of human T-cell leukemia virus type 1 X region proteins in immortalization of primary human lymphocytes in culture. J Virol (1992) 2.21
Requirement of the Pr55gag precursor for incorporation of the Vpr product into human immunodeficiency virus type 1 viral particles. J Virol (1994) 2.20
Circularization of human immunodeficiency virus type 1 DNA in vitro. J Virol (1991) 2.14
Design, intracellular expression, and activity of a human anti-human immunodeficiency virus type 1 gp120 single-chain antibody. Proc Natl Acad Sci U S A (1993) 2.10
Envelope glycoprotein and CD4 independence of vpu-facilitated human immunodeficiency virus type 1 capsid export. J Virol (1992) 2.05
Genomic changes associated with antigenic variation of visna virus durig persistent infection. Proc Natl Acad Sci U S A (1980) 2.04
Trans-activator gene of HTLV-II induces IL-2 receptor and IL-2 cellular gene expression. Science (1986) 2.03
Polymorphism of the 3' open reading frame of the virus associated with the acquired immune deficiency syndrome, human T-lymphotropic virus type III. Nucleic Acids Res (1985) 2.01
A tripartite HIV-1 tat-env-rev fusion protein. EMBO J (1990) 2.01
Use of exonuclease III to determine the site of stable lesions in defined sequences of DNA: the cyclobutane pyrimidine dimer and cis and trans dichlorodiammine platinum II examples. Nucleic Acids Res (1981) 1.97
Novel leukaemogenic retroviruses isolated from cell line derived from spontaneous AKR tumour. Nature (1981) 1.97
Construction and use of a replication-competent human immunodeficiency virus (HIV-1) that expresses the chloramphenicol acetyltransferase enzyme. Proc Natl Acad Sci U S A (1989) 1.96
Terminal redundancy and the origin of replication of Rous sarcoma virus RNA. Proc Natl Acad Sci U S A (1977) 1.94
Comparison of the cleavage of pyrimidine dimers by the bacteriophage T4 and Micrococcus luteus UV-specific endonucleases. J Biol Chem (1980) 1.92
Effects of long terminal repeat mutations on human immunodeficiency virus type 1 replication. J Virol (1989) 1.91
Biochemical evidence that "new" influenza virus strains in nature may arise by recombination (reassortment). Proc Natl Acad Sci U S A (1978) 1.86
Transepithelial transport of HIV-1 by intestinal M cells: a mechanism for transmission of AIDS. J Acquir Immune Defic Syndr (1991) 1.85
Expression of reverse transcriptase activity of human T-lymphotropic virus type III (HTLV-III/LAV) in Escherichia coli. J Virol (1986) 1.84
A new relaxed mutant of Escherichia coli with an altered 50S ribosomal subunit. Proc Natl Acad Sci U S A (1974) 1.83