This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Karnezis, T. Articles by Stanisich, V. A. Search for Related Content PubMed PubMed Citation Articles by Karnezis, T. Articles by Stanisich, V. A.

Cloning and Characterization of the Phosphatidylserine Synthase Gene of Agrobacterium sp. Strain ATCC 31749 and Effect of Its Inactivation on Production of High-Molecular-Mass (13)-ß-D-Glucan (Curdlan)

Departments of Biochemistry,¹ Microbiology, La Trobe University, Melbourne, Victoria 3086, Australia²

Received 15 January 2002/ Accepted 24 April 2002

Genes involved in the production of the extracellular (13)-ß-glucan, curdlan, by Agrobacterium sp. strain ATCC 31749 were described previously (Stasinopoulos et al., Glycobiology 9:31-41, 1999). To identify additional curdlan-related genes whose protein products occur in the cell envelope, the transposon TnphoA was used as a specific genetic probe. One mutant was unable to produce high-molecular-mass curdlan when a previously uncharacterized gene, pss_AG, encoding a 30-kDa, membrane-associated phosphatidylserine synthase was disrupted. The membranes of the mutant lacked phosphatidylethanolamine (PE), whereas the phosphatidylcholine (PC) content was unchanged and that of both phosphatidylglycerol and cardiolipin was increased. In the mutant, the continued appearance of PC revealed that its production by this Agrobacterium strain is not solely dependent on PE in a pathway controlled by the Pss_AG protein at its first step. Moreover, PC can be produced in a medium lacking choline. When the pss_AG::TnphoA mutation was complemented by the intact pss_AG gene, both the curdlan deficiency and the phospholipid profile were restored to wild-type, demonstrating a functional relationship between these two characteristics. The effect of the changed phospholipid profile could occur through an alteration in the overall charge distribution on the membrane or a specific requirement for PE for the folding into or maintenance of an active conformation of any or all of the structural proteins involved in curdlan production or transport.

This article has been cited by other articles:

• Hacker, S., Sohlenkamp, C., Aktas, M., Geiger, O., Narberhaus, F. (2008). Multiple Phospholipid N-Methyltransferases with Distinct Substrate Specificities Are Encoded in Bradyrhizobium japonicum. J. Bacteriol. 190: 571-580 [Abstract] [Full Text]  
• Sohlenkamp, C., de Rudder, K. E. E., Geiger, O. (2004). Phosphatidylethanolamine Is Not Essential for Growth of Sinorhizobium meliloti on Complex Culture Media. J. Bacteriol. 186: 1667-1677 [Abstract] [Full Text]  
• Martinez-Morales, F., Schobert, M., Lopez-Lara, I. M., Geiger, O. (2003). Pathways for phosphatidylcholine biosynthesis in bacteria. Microbiology 149: 3461-3471 [Abstract] [Full Text]  
• Karnezis, T., Epa, V. C., Stone, B. A., Stanisich, V. A. (2003). Topological characterization of an inner membrane (1->3)-{beta}-D-glucan (curdlan) synthase from Agrobacterium sp. strain ATCC31749. Glycobiology 13: 693-706 [Abstract] [Full Text]  
• Campanale, N., Nickel, C., Daubenberger, C. A., Wehlan, D. A., Gorman, J. J., Klonis, N., Becker, K., Tilley, L. (2003). Identification and Characterization of Heme-interacting Proteins in the Malaria Parasite, Plasmodium falciparum. J. Biol. Chem. 278: 27354-27361 [Abstract] [Full Text]