The role of a methyl-accepting chemotaxis protein in gliding motility of the cyanobacterium Synechocystis sp. PCC 68,The role of a methyl-accepting chemotaxis protein in gliding motility of the cyanobacterium Synechocystis sp. PCC 68

Abstract

We found strong evidence that methyl-accepting chemotaxis protein influenced gliding motility of Synechocystis sp. PCC 6803. Random Tn5 mutagenesis was carried out to search for genes involved in phototactic gliding movement. Among the pool of 4,500 Tn5 mutants, we initially isolated 35 nongliding mutants on the agar surface. Using inverse PCR method, it was found that the slr1044 gene (Cyanobase, http://www.kazusa.or.jp/cyano/) encoding a putative methyl-accepting chemotaxis protein was disrupted in one of the nongliding Tn5 mutant, S1-105. It was also confirmed by interposon mutagenesis that the slr1044 gene was responsible for the gliding movement in Synechocystis. The slr1044 gene, renamed ctr1 (cyanobacterial transducer), was a part of gene cluster, which shows homology to pil gene cluster of P. aeruginosa , and was required for the normal expression of pilA1. In slr1044 inactivation mutant, the pilA1 gene expression was 4-fold decreased compared with that of wild-type. These data suggest that the ctr1 gene is a part of a signal transduction network involved in pili production and gliding motility of the cyanobacterium Synechocystis sp. PCC 6803.