The Nudix hydrolase CDP-chase, a CDP-choline pyrophosphatase, is an asymmetric dimer with two distinct enzymatic activities.

ABSTRACT: A Nudix enzyme from Bacillus cereus (NCBI RefSeq accession no. NP_831800) catalyzes the hydrolysis of CDP-choline to produce CMP and phosphocholine. Here, we show that in addition, the enzyme has a 3'→5' RNA exonuclease activity. The structure of the free enzyme, determined to a 1.8-Å resolution, shows that the enzyme is an asymmetric dimer. Each monomer consists of two domains, an N-terminal helical domain and a C-terminal Nudix domain. The N-terminal domain is placed relative to the C-terminal domain such as to result in an overall asymmetric arrangement with two distinct catalytic sites: one with an "enclosed" Nudix pyrophosphatase site and the other with a more open, less-defined cavity. Residues that may be important for determining the asymmetry are conserved among a group of unchara

SUBMITTER: Duong-Ly KC 

PROVIDER: S-EPMC3133267 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature