title: A protein component at the heart of an RNA machine: the importance of protein l27 for the function of the bacterial ribosome.
abstract: Deletion of the gene for protein L27 from the E. coli chromosome results in severe defects in cell growth. This deficiency is corrected by the expression of wild-type (wt) protein L27 from a plasmid. Examination of strains expressing L27 variants truncated at the N terminus reveals that the absence of as few as three amino acids leads to a decrease in growth rate, an impairment in peptidyl transferase activity, and a sharp decline in the labeling of L27 from the 3' end of a photoreactive tRNA at the ribosomal P site. These findings suggest that the flexible N-terminal sequence of L27, which protrudes onto the interface of the bacterial 50S subunit, can reach the peptidyl transferase active site and contribute to its function, possibly by helping to correctly position tRNA substrates at the catalytic site.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Massachusetts, 710 North Pleasant Street, Amherst, Massachusetts 01003, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Maguire
authors.forename: Artemy D
authors.initials: AD
authors.lastname: Beniaminov
authors.forename: Haripriya
authors.initials: H
authors.lastname: Ramu
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Mankin
authors.forename: Robert A
authors.initials: RA
authors.lastname: Zimmermann
mesh_terms: D001665:Binding Sites / Q000502:physiology; D002876:Chromosomes, Bacterial / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D010458:Peptidyl Transferases / Q000235:genetics / Q000378:metabolism; D014176:Protein Biosynthesis / Q000502:physiology; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012269:Ribosomal Proteins; C034661:ribosomal proteins L27; D012343:RNA, Transfer; D010458:Peptidyl Transferases