Unusual evolutionary history of the tRNA splicing endonuclease EndA: relationship to the LAGLIDADG and PD-(D/E)XK deoxyribonucleases.

ABSTRACT: The tRNA splicing endoribonuclease EndA from Methanococcus jannaschii is a homotetramer formed via heterologous interaction between the two pairs of homodimers. Each monomer consists of two alpha/beta domains, the N-terminal domain (NTD) and the C-terminal domain (CTD) containing the RNase A-like active site. Comparison of the EndA coordinates with the publicly available protein structure database revealed the similarity of both domains to site-specific deoxyribonucleases: the NTD to the LAGLIDADG family and the CTD to the PD-(D/E)XK family. Superposition of the NTD on the catalytic domain of LAGLIDADG homing endonucleases allowed a suggestion to be made about which amino acid residues of the tRNA splicing nuclease might participate in formation of a presumptive cryptic deoxyribonuclease a

SUBMITTER: Bujnicki JM 

PROVIDER: S-EPMC2374129 | biostudies-literature | 2001 Mar

REPOSITORIES: biostudies-literature