title: Peptidyl-prolyl-tRNA at the ribosomal P-site reacts poorly with puromycin.
abstract: Despite remarkable recent progress in our chemical and structural understanding of the mechanisms of peptide bond formation by the ribosome, only very limited information is available about whether amino acid side chains affect the rate of peptide bond formation. Here, we generated a series of peptidyl-tRNAs that end with different tRNA-attached amino acids in the P-site of the Escherichia coli ribosome and compared their reactivity with puromycin, a rapidly A-site-accessing analog of aminoacyl-tRNAs. Among the 20 amino acids examined, proline was found to receive exceptionally slow peptidyl transfer to puromycin. These results raise a possibility that the peptidyl transferase activity of the ribosome may have some specificity with regard to the P-site amino acids.
authors.affiliation: Institute for Virus Research, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Muto
authors.forename: Koreaki
authors.initials: K
authors.lastname: Ito
mesh_terms: D019943:Amino Acid Substitution; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D050505:Mutant Proteins / Q000378:metabolism; D009693:Nucleic Acid Hybridization; D011392:Proline / Q000031:analogs & derivatives; D011691:Puromycin / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D050505:Mutant Proteins; D012346:RNA, Transfer, Amino Acyl; C019037:tRNA, peptidyl-; C078167:OMPA outer membrane proteins; D011691:Puromycin; D011392:Proline