Structure of Escherichia coli ribosomal protein L25 complexed with a 5S rRNA fragment at 1.8-A resolution.

ABSTRACT: The crystal structure of Escherichia coli ribosomal protein L25 bound to an 18-base pair portion of 5S ribosomal RNA, which contains "loop E," has been determined at 1.8-A resolution. The protein primarily recognizes a unique RNA shape, although five side chains make direct or water-mediated interactions with bases. Three beta-strands lie in the widened minor groove of loop E formed by noncanonical base pairs and cross-strand purine stacks, and an alpha-helix interacts in an adjacent widened major groove. The structure of loop E is largely the same as that of uncomplexed RNA (rms deviation of 0.4 A for 11 base pairs), and 3 Mg(2+) ions that stabilize the noncanonical base pairs lie in the same or similar locations in both structures. Perhaps surprisingly, those residues interacting with th

SUBMITTER: Lu M 

PROVIDER: S-EPMC15747 | biostudies-literature | 2000 Feb

REPOSITORIES: biostudies-literature