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.