Identification of a novel nutrient-deprivation-induced Sinorhizobium meliloti gene (hmgA) involved in the degradation of tyrosine

• Published in: Microbiology (Society for General Microbiology) 1999-04, Vol.145 (4), p.935-947
• Main Authors: Milcamps, Anne, de Bruijn, Frans J
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacteriology; Biological and medical sciences; cis-trans-Isomerases - chemistry; cis-trans-Isomerases - genetics; cis-trans-Isomerases - metabolism; Dioxygenases; DNA Transposable Elements - genetics; Fundamental and applied biological sciences. Psychology; Genes, Bacterial; Genetics; Homogentisate 1,2-Dioxygenase; Homogentisic Acid - metabolism; Humans; Luciferases - genetics; Luciferases - metabolism; Microbiology; Molecular Sequence Data; Multigene Family; Mutagenesis; Oxygenases - chemistry; Oxygenases - genetics; Oxygenases - metabolism; Sequence Alignment; Sequence Analysis, DNA; Sinorhizobium meliloti; Sinorhizobium meliloti - genetics; Sinorhizobium meliloti - growth & development; Sinorhizobium meliloti - metabolism; Tyrosine - metabolism
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/13500872-145-4-935

NSF Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA Department of Microbiology, Michigan State University, East Lansing, MI 48824, USA Author for correspondence: Frans J. de Bruijn (MSU-DOE Plant Research Laboratory). Fax: [phone]. e-mail: [e-mail] ABSTRACT Summary: Sinorhizobium meliloti strain N4 carries a Tn5 luxAB insertion in a gene which is induced by nitrogen and carbon deprivation as well as in the presence of tyrosine. The Tn 5luxAB -tagged locus was found to share significant similarity with the human hmgA gene and the corresponding Aspergillus nidulans gene, encoding the enzyme homogentisate dioxygenase, which is involved in the degradation of tyrosine. Extended DNA sequence analysis of the tagged locus revealed the presence of several ORFs, including one encoding a polypeptide sharing a high degree of similarity with human and fungal maleylacetoacetate isomerases. Strain N4 was found to be unable to use tyrosine as carbon source, to lack homogentisate dioxygenase activity, to produce a melanin-like pigment and to be affected in stationary-phase survival. This is believed to be the first report of a hmgA -homologous gene in bacteria. Keywords: Rhizobium , starvation, homogentisate dioxygenase, maleylacetoacetate isomerase, glutathione S-transferase