Unraveling the biochemistry and provenance of pupylation: a prokaryotic analog of ubiquitination.

ABSTRACT:

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Recently Mycobacterium tuberculosis was shown to possess a novel protein modification, in which a small protein Pup is conjugated to the epsilon-amino groups of lysines in target proteins. Analogous to ubiquitin modification in eukaryotes, this remarkable modification recruits proteins for degradation via archaeal-type proteasomes found in mycobacteria and allied actinobacteria. While a mycobacterial protein named PafA was found to be required for this conjugation reaction, its biochemical mechanism has not been elucidated. Using sensitive sequence profile comparison methods we establish that the PafA family proteins are related to the gamma-glutamyl-cysteine synthetase and glutamine synthetase. Hence, we predict that PafA is the Pup ligase, which catalyzes the ATP-depen

SUBMITTER: Iyer LM 

PROVIDER: S-EPMC2588565 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature