A chemotaxis cluster from Agrobacterium tumefaciens

• Published in: Gene Vol. 220; no. 1; pp. 83 - 89
• Main Authors: Wright, Emma L, Deakin, William J, Shaw, Charles H
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.10.1998
• Subjects: Agrobacterium; AGROBACTERIUM TUMEFACIENS; Agrobacterium tumefaciens - genetics; Bacterial Proteins - genetics; CHEMOTAXIS; Chemotaxis - genetics; Flagella; GENE; GENES; Genes, Bacterial; MECANISME CHIMIOTACTIQUE; Membrane Proteins - genetics; Methyl-Accepting Chemotaxis Proteins; Motility; MOUVEMENT; MOVEMENT; MOVIMIENTO; Multigene Family - genetics; Mutagenesis, Site-Directed; NUCLEOTIDE SEQUENCE; Phenotype; QUIMIOTACTISMO; RHIZOBIUM MELILOTI; SECUENCIA NUCLEOTIDICA; SEQUENCE NUCLEOTIDIQUE; bp, basepair(s); aa, amino acid(s); vir, Agrobacterium virulence gene; Motility; CheA, chemotaxis protein; T-DNA, Ti-plasmid transfer or tumour DNA; cheA, gene encoding CheA; kb, kilobase(s) or 1000 bp; S., Sinorhizobium; Chemotaxis; C., Caulobacter; Agrobacterium; E., Escherichia; A., Agrobacterium; R., Rhodobacter; Ti-plasmid, Agrobacterium tumour-inducing plasmid; Flagella; orf, open reading frame
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/S0378-1119(98)00438-7

We report the DNA sequence of a 9.6-kb region of the Agrobacterium tumefaciens chromosome containing a putative 8-kb chemotaxis operon. The putative operon begins with orf1, whose predicted protein product shows strong sequence identity to methyl-accepting chemotaxis proteins (MCPs), followed by orf2, cheY1, cheA, cheR, cheB, cheY2, orf9, orf10. All of the identified homologues show a high degree of sequence conservation with their counterparts in the che operons from Sinorhizobium meliloti and Rhodobacter sphaeroides, and are arranged in a similar order. Mutations in orf1 and cheA result in impaired chemotaxis, whereas deletion of orf10, appears to have no effect on chemotaxis or motility. Although the putative operon does not contain a cheW homologue, heterologous probing and PCR using consensus primers indicates that cheW maps elsewhere in the Agrobacterium genome.