Analysis of the human polynucleotide phosphorylase (PNPase) reveals differences in RNA binding and response to phosphate compared to its bacterial and chloroplast counterparts.

ABSTRACT: PNPase is a major exoribonuclease that plays an important role in the degradation, processing, and polyadenylation of RNA in prokaryotes and organelles. This phosphorolytic processive enzyme uses inorganic phosphate and nucleotide diphosphate for degradation and polymerization activities, respectively. Its structure and activities are similar to the archaeal exosome complex. The human PNPase was recently localized to the intermembrane space (IMS) of the mitochondria, and is, therefore, most likely not directly involved in RNA metabolism, unlike in bacteria and other organelles. In this work, the degradation, polymerization, and RNA-binding properties of the human PNPase were analyzed and compared to its bacterial and organellar counterparts. Phosphorolytic activity was displayed at lower o

SUBMITTER: Portnoy V 

PROVIDER: S-EPMC2212259 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature