Aspartate carbamoyltransferase from a psychrophilic deep-sea bacterium, Vibrio strain 2693: properties of the enzyme, genetic organization and synthesis in Escherichia coli

• Published in: Microbiology (Society for General Microbiology) Vol. 144; no. 5; pp. 1435 - 1441
• Main Authors: Xu, Ying, Zhang, Yuanfu, Liang, Ziyuan, Van de Casteele, Mark, Legrain, Christianne, Glansdorff, Nicolas
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01-05-1998; Society for General Microbiology
• Subjects: Amino Acid Sequence; Aspartate Carbamoyltransferase - biosynthesis; Aspartate Carbamoyltransferase - chemistry; Aspartate Carbamoyltransferase - genetics; Aspartate Carbamoyltransferase - metabolism; Bacteriology; Biological and medical sciences; Cloning, Molecular; Cold Temperature; DNA, Bacterial; Enterobacteriaceae; Escherichia coli; Escherichia coli - enzymology; Escherichia coli - genetics; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetics; Marine; Microbiology; Molecular Sequence Data; Operon; Promoter Regions, Genetic; Pyrococcus abyssi; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Structure-Activity Relationship; Temperature; Transcription, Genetic; Transformation, Bacterial; Vibrio; Vibrio - chemistry; Vibrio - enzymology; Vibrio - genetics; Vibrio - growth & development; Nucleotide sequence; Enzyme; Psychrophily; Operon; Transferases; Aspartate carbamoyltransferase; Bacteria; Vibrionaceae; Gene organization; Gene expression; Aminoacid sequence; Vibrio
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-144-5-1435

Microbiologie, Vrije Universiteit Brussel B-1070 Brussels, Belgium
Flanders Interuniversity Institute for Biotechnology B-1070 Brussels, Belgium
Research Institute CERIA-COOVI Emile Grysonlaan 1, B-1070 Brussels, Belgium
Epidemiology Institute, Beijing, The Peoples Republic of China
ABSTRACT
The aspartate carbamoyltransferase (ATCase) genes of psychrophilic Vibrio strain 2693 were cloned by complementation in Escherichia coli and the enzyme was partly characterized. The genes constitute a pyrBl operon homologous to the cognate structure in E. coli where pyrB and pyrl respectively encode the catalytic and the regulatory chains of ATCase. The strong sequence similarities noted between Vibrio and E. coli ATCases include extensive conservation of residues involved in interactions between subunits, suggesting that the two enzymes have very similar tertiary and quaternary structures. Vibrio ATCase is, however, not activated by ATP and not synergistically inhibited by CTP and UTP. It is also much more thermolabile than E. coli ATCase. With respect to Pyrococcus abyssi and E. coli ATCases, Vibrio ATCase presents marked differences in composition which could be related to its psychrophilic character. The results of these structural and functional comparisons indicate that Vibrio 2693 ATCase is a suitable model for biochemical studies on structure-function relationships in a ‘cold’ allosteric enzyme. The operon is expressed from a promoter which is immediately followed by a pyrimidine-rich leader ORF terminating within a putative transcription attenuator. These genetic and enzymic data strengthen the evolutionary relationship already noted between Vibrionaceae and Enterobacteriaceae.
* Author for correspondence: Nicolas Glansdorff. Tel: [phone]. Fax: [phone]. e-mail: [e-mail]
Keywords: aspartate carbamoyltransferase, psychrophiles, Vibrio