A eukaryote-like cardiolipin synthase is present in Streptomyces coelicolor and in most actinobacteria.

ABSTRACT: Cardiolipin (CL) is an anionic membrane lipid present in bacteria, plants, and animals, but absent from archaea. It is generally thought that bacteria use an enzyme belonging to the phospholipase D superfamily as cardiolipin synthase (Cls) catalyzing a reversible phosphatidyl group transfer from one phosphatidylglycerol (PG) molecule to another PG to form CL and glycerol. In contrast, in eukaryotes a Cls of the CDP-alcohol phosphatidyltransferase superfamily uses cytidine diphosphate-diacylglycerol (CDP-DAG) as the donor of the phosphatidyl group, which is transferred to a molecule of PG to form CL. Searching the genome of the actinomycete Streptomyces coelicolor A3(2) we identified a gene coding for a putative Cls of the CDP-alcohol phosphatidyltransferase superfamily (Sco1389). Here we show that expression of Sco1389 in a CL-deficient Rhizobium etli mutant restores CL formation. In an in vitro assay Sco1389 condenses CDP-DAG with PG to form CL and therefore catalyzes the same reaction as eukaryotic cardiolipin synthases. This is the first time that a CDP-alcohol phosphatidyltransferase from bacteria is shown to be responsible for CL formation. The broad occurrence of putative orthologues of Sco1389 among the actinobacteria suggests that CL synthesis involving a eukaryotic type Cls is common in actinobacteria.

SUBMITTER: Sandoval-Calderon M 

PROVIDER: S-EPMC2719378 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature