Structural and putative regulatory genes involved in cellulose synthesis in Rhizobium leguminosarum bv. trifolii.
Six genes involved in cellulose synthesis in Rhizobium leguminosarum bv. trifolii were identified using Tn5 mutagenesis. Four of them displayed homology to the previously cloned and sequenced Agrobacterium tumefaciens cellulose genes celA, celB, celC and celE. These genes are organized similarly in R. leguminosarum bv. trifolii. In addition, there were strong indications that two tandemly located genes, celR1 and celR2, probably organized as one operon, are involved in the regulation of cellulose synthesis. The deduced amino acid sequences of these genes displayed a high degree of similarity to the Caulobacter crescentus DivK and PleD proteins that belong to the family of two-component response regulators. This is to our knowledge the first report of genes involved in the regulation of cellulose synthesis. Results from attachment assays and electron microscopic studies indicated that cellulose synthesis in R. leguminosarum bv. trifolii is induced upon close contact with plant roots during the attachment process.
Ausmees
Nora
N
Swedish University of Agricultural Sciences, SLU, Department of Microbiology, Box 7025, S-75007 Uppsala, Sweden.
Jonsson
Hans
H
Swedish University of Agricultural Sciences, SLU, Department of Microbiology, Box 7025, S-75007 Uppsala, Sweden.
Höglund
Stefan
S
Uppsala University, Department of Biochemistry, Box 576, S-75123 Uppsala, Sweden.
Ljunggren
Hans
H
Swedish University of Agricultural Sciences, SLU, Department of Microbiology, Box 7025, S-75007 Uppsala, Sweden.
Lindberg
Martin
M
Swedish University of Agricultural Sciences, SLU, Department of Microbiology, Box 7025, S-75007 Uppsala, Sweden.
D000595:Amino Acid Sequence; D002482:Cellulose / Q000096:biosynthesis*; D004251:DNA Transposable Elements; D007887:Fabaceae / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005809:Genes, Regulator; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010946:Plants, Medicinal; D016961:Rhizobium leguminosarum / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D004251:DNA Transposable Elements; D002482:Cellulose