HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Cánovas, D. Articles by Nieto, J. J. Search for Related Content PubMed PubMed Citation Articles by Cánovas, D. Articles by Nieto, J. J. Agricola Articles by Cánovas, D. Articles by Nieto, J. J.

Genes for the synthesis of the osmoprotectant glycine betaine from choline in the moderately halophilic bacterium Halomonas elongata DSM 3043

Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, 41012 Seville, Spain¹
Laboratory for Microbiology, Department of Biology, Philipps University, MarburgD-35032, Marburg, Germany²

Author for correspondence: Joaquín J. Nieto. Tel: +34 95 4556765. Fax: +34 954 628162. e-mail: jjnieto{at}cica.es

The genes involved in the oxidative pathway of choline to glycine betaine in the moderate halophile Halomonas elongata DSM 3043 were isolated by functional complementation of an Escherichia coli strain defective in glycine betaine synthesis. The cloned region was able to mediate the oxidation of choline to glycine betaine in E. coli, but not the transport of choline, indicating that the gene(s) involved in choline transport are not clustered with the glycine betaine synthesis genes. Nucleotide sequence analysis of a 4·6 kb segment from the cloned DNA revealed the occurrence of three ORFs (betIBA) apparently arranged in an operon. The deduced betI gene product exhibited features typical for DNA-binding regulatory proteins. The deduced BetB and BetA proteins showed significant similarity to soluble glycine betaine aldehyde dehydrogenases and membrane-bound choline dehydrogenases, respectively, from a variety of organisms. Evidence is presented that BetA is able to oxidize both choline and glycine betaine aldehyde and therefore can mediate both steps in the synthesis of glycine betaine.

Keywords: moderate halophiles, Halomonas elongata, bet genes, osmoregulation, compatible solutes

Abbreviations: BADH, glycine betaine aldehyde dehydrogenase; CDH, choline dehydrogenase

The EMBL accession number for the sequence reported in this paper is AJ238780.

^a Present address: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología, CSIC, Cantoblanco, 28049 Madrid, Spain.

This article has been cited by other articles:

				M. Jebbar, L. Sohn-Bosser, E. Bremer, T. Bernard, and C. Blanco Ectoine-Induced Proteins in Sinorhizobium meliloti Include an Ectoine ABC-Type Transporter Involved in Osmoprotection and Ectoine Catabolism J. Bacteriol., February 15, 2005; 187(4): 1293 - 1304. [Abstract] [Full Text] [PDF]

				M. I. Calderon, C. Vargas, F. Rojo, F. Iglesias-Guerra, L. N. Csonka, A. Ventosa, and J. J. Nieto Complex regulation of the synthesis of the compatible solute ectoine in the halophilic bacterium Chromohalobacter salexigens DSM 3043T Microbiology, September 1, 2004; 150(9): 3051 - 3063. [Abstract] [Full Text] [PDF]

				K. J. Pflughoeft, K. Kierek, and P. I. Watnick Role of Ectoine in Vibrio cholerae Osmoadaptation Appl. Envir. Microbiol., October 1, 2003; 69(10): 5919 - 5927. [Abstract] [Full Text] [PDF]

				G. Gadda and E. E. McAllister-Wilkins Cloning, Expression, and Purification of Choline Dehydrogenase from the Moderate Halophile Halomonas elongata Appl. Envir. Microbiol., April 1, 2003; 69(4): 2126 - 2132. [Abstract] [Full Text] [PDF]