4hvj
From Proteopedia
Crystal structure of a putative uncharacterized protein from Mycobacterium tuberculosis in complex with AMP
Structural highlights
FunctionEXRBN_MYCTU Exonuclease that cleaves single-stranded 3' overhangs of double-stranded RNA. Has no activity with 5' overhangs. Has negligible endonuclease activity. Can bind ATP, dATP and AMP (in vitro); the nucleotide occupies the predicted substrate binding site.[1] Publication Abstract from PubMedRibonucleases (RNases) maintain the cellular RNA pool by RNA processing and degradation. In many bacteria including the human pathogen Mycobacterium tuberculosis (Mtb), the enzymes mediating several central RNA processing functions are still unknown. Here, we identify the hypothetical Mtb protein Rv2179c as a highly divergent exoribonuclease. Although the primary sequence of Rv2179c has no detectable similarity to any known RNase, the Rv2179c crystal structure reveals an RNase fold. Active site residues are equivalent to those in the DEDD family of RNases, and Rv2179c has close structural homology to E. coli RNase T. Consistent with the DEDD fold, Rv2179c has exoribonuclease activity, cleaving the 3' single strand overhangs of duplex RNA. Functional orthologs of Rv2179c are prevalent in actinobacteria and found in bacteria as phylogentically distant as proteobacteria. Thus, Rv2179c is the founding member of a new, large RNase family with hundreds of members across the bacterial kingdom. Mycobacterium tuberculosis Rv2179c establishes a new exoribonuclease family with broad phylogenetic distribution.,Abendroth J, Ollodart A, Andrews ES, Myler PJ, Staker BL, Edwards TE, Arcus VL, Grundner C J Biol Chem. 2013 Dec 4. PMID:24311791[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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