Organization of carbamoyl-phosphate synthase genes in Neisseria gonorrhoeae includes a large, variable intergenic sequence which is also present in other Neisseria species

• Published in: Microbiology (Society for General Microbiology) 1995-05, Vol.141 (5), p.1183-1191
• Main Authors: Lawson, Fiona S, Billowes, Finola M, Dillon, Jo-Anne R
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacteriology; Base Sequence; Biological and medical sciences; Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) - biosynthesis; Carbamoyl-Phosphate Synthase (Glutamine-Hydrolyzing) - genetics; Cloning, Molecular; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetics; Introns; Microbiology; Molecular Sequence Data; Neisseria - genetics; Neisseria - isolation & purification; Neisseria gonorrhoeae - enzymology; Neisseria gonorrhoeae - genetics; Nucleic Acid Conformation; Recombinant Proteins - biosynthesis; Restriction Mapping; Sequence Homology, Amino Acid; Species Specificity
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/13500872-141-5-1183

1 Department of Biology, University of Ottawa, Ottawa, Ontario, Canada 2 National Laboratory for Sexually Transmitted Diseases, Laboratory Centre for Disease Control, Ottawa, Ontario, Canada 5 Author for correspondence: Jo-Anne R. Dillon. Tel: [phone]. Fax: [phone]. e-mail: [e-mail] ABSTRACT The carbamoyl-phosphate synthase (CPS) enzyme in prokaryotes is a heterodimer, encoded by genes commonly called carA and carB . In most prokaryotes examined, these genes are separated by up to 24 bp and are cotranscribed. In Pseudomonas aeruginosa, carA and carB are also co-transcribed, but are separated by 682 bp. We have determined the complete DNA sequence of the carA and carB genes of Neisseria gonorrhoeae strain CH811. carA (1125 bp) and carB (3237 bp) are similar in size and sequence to other prokaryotic CPS genes, however they are separated by an intervening sequence of 3290 bp which has no similarity to the intervening sequence between other CPS genes; furthermore, putative transcription terminators are found downstream of both carA and carB . Several neisserial repetitive sequences were identified within the 9 kb sequenced, as well as novel 120 and 150 bp repeats (designated RS6 and RS7, respectively) which were found within the intervening sequence between carA and carB . To determine whether the intervening sequence observed in N. gonorrhoeae CH811 was not unusual, the sequence between carA and carB was amplified by PCR from 30 isolates of N. gonorrhoeae . The intervening sequence was found to vary in size, from approximately 2:2 to 3:7 kb, although the carA and carB genes themselves did not vary in size in isolates with functional CPS enzyme. A similar large, variably sized intervening sequence was also found between the carA and carB genes of 12 isolates of N. meningitidis and 18 commensal Neisseria isolates comprising nine species. This unexpected organization of the CPS genes in N. gonorrhoeae is therefore widespread throughout the genus Neisseria . Keywords: Neisseria gonorrhoeae, carbamoyl-phosphate synthase (glutamine-hydrolysing), arginine biosynthesis, pyrimidine biosynthesis, Neisseria species Present address: Department of Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario, Canada, K1H 8M5