2c5u

Publication Abstract from PubMed

RNA ligase type 1 from bacteriophage T4 (Rnl1) is involved in countering a host defense mechanism by repairing 5'-PO4 and 3'-OH groups in tRNA(Lys). Rnl1 is widely used as a reagent in molecular biology. Although many structures for DNA ligases are available, only fragments of RNA ligases such as Rnl2 are known. We report the first crystal structure of a complete RNA ligase, Rnl1, in complex with adenosine 5'-(alpha,beta-methylenetriphosphate) (AMPcPP). The N-terminal domain is related to the equivalent region of DNA ligases and Rnl2 and binds AMPcPP but with further interactions from the additional N-terminal 70 amino acids in Rnl1 (via Tyr37 and Arg54) and the C-terminal domain (Gly269 and Asp272). The active site contains two metal ions, consistent with the two-magnesium ion catalytic mechanism. The C-terminal domain represents a new all alpha-helical fold and has a charge distribution and architecture for helix-nucleic acid groove interaction compatible with tRNA binding.

Molecular architecture and ligand recognition determinants for T4 RNA ligase.,El Omari K, Ren J, Bird LE, Bona MK, Klarmann G, LeGrice SF, Stammers DK J Biol Chem. 2006 Jan 20;281(3):1573-9. Epub 2005 Nov 1. PMID:16263720^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.