title: Mycobacterium tuberculosis Rv2179c protein establishes a new exoribonuclease family with broad phylogenetic distribution.
abstract: Ribonucleases (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 Escherichia 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 phylogenetically distant as proteobacteria. Thus, Rv2179c is the founding member of a new, large RNase family with hundreds of members across the bacterial kingdom.
authors: From Emerald Bio, Bainbridge Island, Washington 98110.
authors: Jan
authors: J
authors: Abendroth
authors: Anja
authors: A
authors: Ollodart
authors: Emma S V
authors: ES
authors: Andrews
authors: Peter J
authors: PJ
authors: Myler
authors: Bart L
authors: BL
authors: Staker
authors: Thomas E
authors: TE
authors: Edwards
authors: Vickery L
authors: VL
authors: Arcus
authors: Christoph
authors: C
authors: Grundner
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D005095:Exoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000235:genetics; D010802:Phylogeny; D040681:Structural Homology, Protein; D037521:Virulence Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; C578340:Rv2190c protein, Mycobacterium tuberculosis; D037521:Virulence Factors; D005095:Exoribonucleases
keywords: Annotation; Crystal Structure; Microbiology; Mycobacterium tuberculosis; Pseudomonas; Ribonuclease