DivIVA uses an N-terminal conserved region and two coiled-coil domains to localize and sustain the polar growth in Corynebacterium glutamicum

Abstract

Corynebacterium glutamicum is a rod-shaped actinomycete with a distinct model of peptidoglycan synthesis during cell elongation, which takes place at the cell poles and is sustained by the essential protein DivIVACG (C. glutamicum DivIVA). This protein contains a short conserved N-terminal domain and two coiled-coil regions: CC1 and CC2. Domain deletions and chimeric versions of DivIVA were used to functionally characterize the three domains, and all three were found to be essential for proper DivIVACG function. However, in the presence of the N-terminal domain from DivIVACG, either of the two coiled-coil domains of DivIVACG could be replaced by the equivalent coiled-coil domain of Bacillus subtilis DivIVA (DivIVA BS) without affecting the function of the original DivIVA CG, and more than one domain had to be exchanged to lose function. Although no single domain was sufficient for subcellular localization or function, CC1 was mainly implicated in stimulating polar growth and CC2 in targeting to DivIVACG assemblies at the cell poles in C. glutamicum. © 2009 Federation of European Microbiological Societies.