Photochemical cross-linking of the anticodon loop of yeast tRNA(Phe) to 30S-subunit protein S7 at the ribosomal A and P sites.
Yeast tRNA(Phe), containing the photoreactive nucleoside 2-azidoadenosine at position 37 within the anticodon loop, has been cross-linked to the aminoacyl-tRNA (A) and peptidyl-tRNA (P) binding sites of the Escherichia coli ribosome. The 30S subunit was exclusively labeled in each case, and cross-linking occurred to both protein and 16S rRNA. Electrophoretic and immunological analyses demonstrated that S7 was the only 30S-subunit protein covalently attached to the tRNA. However, digestion of the A and P site-labeled S7 with trypsin revealed a unique pattern of cross-linked peptide(s) at each site. Thus, while the anticodon loop of tRNA is in close proximity to protein S7 at both the A and P sites, it neighbors a different portion of the protein molecule in each. The placement of the aminoacyl- and peptidyl-tRNA binding sites is discussed in relationship to recent models of the 30S ribosomal subunit.
Sylvers
L A
LA
Program in Molecular and Cellular Biology, University of Massachusetts, Amherst 01003.
Kopylov
A M
AM
Wower
J
J
Hixson
S S
SS
Zimmermann
R A
RA
D000926:Anticodon / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D001665:Binding Sites; D004926:Escherichia coli; D010777:Photochemistry; D012331:RNA, Fungal / Q000737:chemistry; D012360:RNA, Transfer, Phe / Q000737:chemistry* / Q000528:radiation effects; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000528:radiation effects; D012441:Saccharomyces cerevisiae / Q000235:genetics
D000926:Anticodon; D001426:Bacterial Proteins; D012331:RNA, Fungal; D012360:RNA, Transfer, Phe; D012269:Ribosomal Proteins; C040469:ribosomal protein S30; C037442:ribosomal protein S7