Organization and transcription of the division cell wall (dcw) cluster in Neisseria gonorrhoeae

A cluster of genes involved in cell division and cell wall (dew) biosynthesis was identified in Neisseria gonorrhoeae using genomic analysis and through verification of gene order by polymerase chain reaction (PCR) analysis. The gonococcal dew, cluster consists of 17 genes, in the order 5'-mraZ-mraW-ftsI-murE-hyp1-murY-hyp2-murD-ftsW-murG-murC-ddl-ftsA-ftsZ-hyp3-3'. The gene organization of the dew cluster of N. gonorrhoeae is more similar to that observed in Cram-negative rods such as Escherichia coli and Haemophilus influenzae than in Gram-positive bacteria. The cluster is characterized by several intergenic spaces. Compared with E, coli, two genes, ftsL and envA, are absent in the gonococcal dew cluster and three hypothetical genes are novel to the cluster. The cluster is flanked by two transcriptional termninators consisting of paired neisserial uptake sequences and also includes four internal terminators, three of which are paired neisserial uptake sequences. We also found that a repeated sequence on the gonococcal genome, commonly called a Correia element, acts as the fourth transcriptional terminator. All termination sequences were shown to be fully functional by using reverse transcription PCR experiments. Transcriptional start sites upstream of ftsQ, ftsA and ftsZ were determined by primer extension and six promoters were identified; three promoters were located upstream of ftsZ in the intergenic space, two were upstream of ftsA within frQ and one was upstream of ftsQ within ddl. Some of these promoters were preferentially used under anaerobic conditions. The location of these promoters differed from those described in E. coli indicating dissimilar transcriptional regulation. (C) 2000 Published by Elsevier Science B.V. All rights reserved.