A CDP-choline pathway for phosphatidylcholine biosynthesis in Treponema denticola.
Mol Microbiol
; 51(2): 471-81, 2004 Jan.
Article
em En
| MEDLINE
| ID: mdl-14756787
ABSTRACT
The genomes of Treponema denticola and Treponema pallidum contain a gene, licCA, which is predicted to encode a fusion protein containing choline kinase and CTPphosphocholine cytidylyltransferase activities. Because both organisms have been reported to contain phosphatidylcholine, this raises the possibility that they use a CDP-choline pathway for the biosynthesis of phosphatidylcholine. This report shows that phosphatidylcholine is a major phospholipid in T. denticola, accounting for 35-40% of total phospholipid. This organism readily incorporated [14C]choline into phosphatidylcholine, indicating the presence of a choline-dependent biosynthetic pathway. The licCA gene was cloned, and recombinant LicCA had choline kinase and CTPphosphocholine cytidylyltransferase activity. The licCA gene was disrupted in T. denticola by erythromycin cassette mutagenesis, resulting in a viable mutant. This disruption completely blocked incorporation of either [14C]choline or 32Pi into phosphatidylcholine. The rate of production of another phospholipid in T. denticola, phosphatidylethanolamine, was elevated considerably in the licCA mutant, suggesting that the elevated level of this lipid compensated for the loss of phosphatidylcholine in the membranes. Thus it appears that T. denticola does contain a licCA-dependent CDP-choline pathway for phosphatidylcholine biosynthesis.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfatidilcolinas
/
Treponema
/
Colina Quinase
/
Colina-Fosfato Citidililtransferase
/
Citidina Difosfato Colina
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2004
Tipo de documento:
Article
País de afiliação:
Estados Unidos