Mycobacterium smegmatis RqlH defines a novel clade of bacterial RecQ-like DNA helicases with ATP-dependent 3′-5′ translocase and duplex unwinding activities Journal Article
| Authors: | Ordonez, H.; Unciuleac, M.; Shuman, S. |
| Article Title: | Mycobacterium smegmatis RqlH defines a novel clade of bacterial RecQ-like DNA helicases with ATP-dependent 3′-5′ translocase and duplex unwinding activities |
| Abstract: | The Escherichia coli RecQ DNA helicase participates in a pathway of DNA repair that operates in parallel to the recombination pathway driven by the multisubunit helicase-nuclease machine RecBCD. The model mycobacterium Mycobacterium smegmatis executes homologous recombination in the absence of its helicase-nuclease machine AdnAB, though it lacks a homolog of E. coli RecQ. Here, we identify and characterize M. smegmatis RqlH, a RecQ-like helicase with a distinctive domain structure. The 691-amino acid RqlH polypeptide consists of a RecQ-like ATPase domain (amino acids 1-346) and tetracysteine zinc-binding domain (amino acids 435-499), separated by an RqlH-specific linker. RqlH lacks the C-terminal HRDC domain found in E. coli RecQ. Rather, the RqlH C-domain resembles bacterial ComF proteins and includes a phosphoribosyltransferase-like module. We show that RqlH is a DNA-dependent ATPase/dATPase that translocates 3′-5′ on single-stranded DNA and has 3′-5′ helicase activity. These functions inhere to RqlH-(1-505), a monomeric motor unit comprising the ATPase, linker and zinc-binding domains. RqlH homologs are distributed widely among bacterial taxa. The mycobacteria that encode RqlH lack a classical RecQ, though many other Actinobacteria have both RqlH and RecQ. Whereas E. coli K12 encodes RecQ but lacks a homolog of RqlH, other strains of E. coli have both RqlH and RecQ. © 2011 The Author(s). |
| Keywords: | controlled study; unclassified drug; nonhuman; protein domain; protein function; carboxy terminal sequence; enzyme activity; structure activity relation; bacterial strain; bacteria (microorganisms); bacterial proteins; dna; double stranded dna; amino acid sequence; molecular sequence data; kinetics; enzyme analysis; escherichia coli; substrate specificity; protein transport; protein structure, tertiary; helicase; recq helicases; adenosine triphosphate; single stranded dna; dna, single-stranded; adenosine triphosphatase; enzyme structure; bacterium identification; mycobacterium; corynebacterineae; genetic code; enzyme localization; metals; phylogeny; mycobacterium smegmatis; cladistics; actinobacteria; recq helicase; species comparison; protein rqih |
| Journal Title: | Nucleic Acids Research |
| Volume: | 40 |
| Issue: | 10 |
| ISSN: | 0305-1048 |
| Publisher: | Oxford University Press |
| Date Published: | 2012-05-01 |
| Start Page: | 4604 |
| End Page: | 4614 |
| Language: | English |
| DOI: | 10.1093/nar/gks046 |
| PROVIDER: | scopus |
| PMCID: | PMC3378886 |
| PUBMED: | 22287622 |
| DOI/URL: | |
| Notes: | --- - "Export Date: 2 July 2012" - "CODEN: NARHA" - "Source: Scopus" |
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