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) biosynthes is was identified in Neisseria gonorrhoeae using genomic analysis and throu gh 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 ge ne organization of the dew cluster of N. gonorrhoeae is more similar to tha t observed in Cram-negative rods such as Escherichia coli and Haemophilus i nfluenzae than in Gram-positive bacteria. The cluster is characterized by s everal intergenic spaces. Compared with E, coli, two genes, ftsL and envA, are absent in the gonococcal dew cluster and three hypothetical genes are n ovel to the cluster. The cluster is flanked by two transcriptional termnina tors consisting of paired neisserial uptake sequences and also includes fou r internal terminators, three of which are paired neisserial uptake sequenc es. We also found that a repeated sequence on the gonococcal genome, common ly called a Correia element, acts as the fourth transcriptional terminator. All termination sequences were shown to be fully functional by using rever se transcription PCR experiments. Transcriptional start sites upstream of f tsQ, ftsA and ftsZ were determined by primer extension and six promoters we re identified; three promoters were located upstream of ftsZ in the interge nic space, two were upstream of ftsA within frQ and one was upstream of fts Q within ddl. Some of these promoters were preferentially used under anaero bic conditions. The location of these promoters differed from those describ ed in E. coli indicating dissimilar transcriptional regulation. (C) 2000 Pu blished by Elsevier Science B.V. All rights reserved.