Altered cell length in deletion mutants of the different divIVA genes in Rhodococcus erythropolis PR4.

Abstract

Unlike other Actinobacteria, Rhodococcus erythropolis PR4 contains three different copies of divIVA genes. The three divIVA genes show about 22-38% similarity with each other. Deletion mutants of the divIVA genes resulted in altered morphology: elongated cells in △divIVA-2 and short rod-shaped cells in △divIVA-1 and △divIVA-3. The expression of the divIVA-2 gene was found to be higher as compared to the divIVA-1 and divIVA-3 genes in wild-type cells. The subcellular localisation studies revealed that the three different DivIVA proteins are spatially present at different regions of cell space. Our results suggest that an interplay of the three DivIVA proteins plays a role in cell shape maintenance in R. erythropolis PR4. Bioinformatics analysis and interactome study show that amongst the three copies of divIVA genes, the second copy, i.e., divIVA-2 gene, might have a more governing function in the cell division process as compared to the other two copies.