期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1986
卷号:83
期号:24
页码:9289-9293
DOI:10.1073/pnas.83.24.9289
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:We have recently demonstrated that two ATP analog affinity labels, 8-azidoadenosine 5'-triphosphate (N3ATP) and 5'-p-fluorosulfonylbenzoyladenosine (5'FSBA), covalently modify RecA protein of Escherichia coli at a specific tyrosine residue (Tyr-264) located within a 24-residue tryptic peptide (T-31) spanning residues 257-280. Here we show that N3ATP efficiently modifies purified peptide T-31 and show that the interaction is specific by the following criteria: photolabeling of peptide T-31 is saturable with respect to the N3ATP concentration; photolabeling is competitive with ATP and adenosine but not with adenine, UTP, or TTP; and other peptides derived from RecA protein were poor substrates for photolabeling except for one fragment that showed a nonspecific interaction with the photoaffinity analog. Analysis of N3ATP-modified T-31 shows that the photolabel attaches to more than one site within the peptide. These data argue that peptide T-31 contains some sites of contact for adenine and ribose moieties of ATP when it is bound to RecA protein.