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- ********************************************************
- * Bacterial regulatory proteins, luxR family signature *
- ********************************************************
-
- The many bacterial transcription regulation proteins which bind DNA through a
- 'helix-turn-helix' motif can be classified into subfamilies on the basis of
- sequence similarities. One of these subfamilies groups together [1,2,3] the
- following proteins (references are only provided for recently determined
- sequences):
-
- - bvgA; Bordetella pertussis; plays a role in virulence.
- - comA; Bacillus subtilis; plays a role in the expression of late-expressing
- competence genes.
- - degU; Bacillus subtilis; activates extracellular proteases genes.
- - evgA; Escherichia coli.
- - expR; Erwinia carotovora; acts in virulence (soft rot disease) through the
- activation of genes for plant tissue macerating enzymes.
- - fimZ; Escherichia coli and Salmonella typhimurium.
- - fixJ; Rhizobiaceae; induces the expression of nifA and fixN.
- - gerE; Bacillus subtilis; regulation of spore formation.
- - gacA; Pseudomonas fluorescens; involved in the regulation of secondary
- metabolism.
- - glpR; Pseudomonas aeruginosa; activates genes of the glycerol metabolic
- pathway.
- - lasR; Pseudomonas aeruginosa; activates the elastase gene (lasB).
- - luxR; Vibrio fischeri; activates the bioluminescence operon.
- - malT; Escherichia coli; activates the maltose operon. MalT binds ATP and
- maltotriose.
- - narL and narP; Escherichia coli; activate the nitrate reductase operon.
- - nodW, Rhizobiaceae; probably regulates the transcription of genes involved
- in the nodulation process.
- - rcsA, Enterobacteria; activates genes for capsular polysaccharide synthesis.
- - rcsB; Enterobacteria; involved in the regulation of capsular polysaccharide
- synthesis.
- - rhiR, Rhizobiaceae; activates the rhiABC operon.
- - sdiA; Escherichia coli; activates the ftsQAZ operon.
- - traR; Agrobacterium tumefaciens; involved in the regulation of Ti plasmid
- transfer.
- - uhpA; Escherichia coli and Salmonella typhimurium; activates the uhpT gene
- for hexose phosphate transport.
- - uvrY, an Escherichia coli hypothetical protein.
- - A hypothetical transcriptional regulator encoded downstream of the trpAB
- genes in Pseudomonas aeruginosa.
-
- The size of these proteins range from 74 amino acids (gerE) to 901 (malT), but
- the majority of them have from 190 to 230 residues. On the basis of the
- mechanism by which they are activated they can be classified into two classes:
-
- - A class of regulators which belong to a two-component sensory transduction
- system where the protein is activated by its phosphorylation, generally on
- an aspartate residue, by a transmembrane kinase. The proteins that belong
- to this class are: bvgA, comA, degU, evgA, fimZ, fixJ, gacA, glpR, narL,
- narP, nodW, rcsB and uhpA.
- - A class of regulators which is activated when bound to the autoinducer
- molecule N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) [4]. The proteins
- that belong to this class are: expR, luxR and traR.
-
- The 'helix-turn-helix' DNA-binding motif of these proteins is located in the
- C-terminal section of the sequences. The pattern we use to detect these
- proteins starts three residues downstream of the N-terminal extremity of the
- helix-turn-helix motif and extend five residues upstream of its C-terminal
- extremity.
-
- -Consensus pattern: [GDC]-x(2)-[NSTAV]-x(2)-[IV]-[GSTA]-x(2)-[LIVMFYWC]-x-
- [LIVMFYWCR]-x(3)-[NST]-[LIVM]-x(5)-[NRHSA]-[LIVMTA]-x(2)-K
- -Sequences known to belong to this class detected by the pattern: ALL, except
- for traR.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: June 1994 / Pattern and text revised.
-
- [ 1] Henikoff S., Wallace J.C., Brown J.P.
- Meth. Enzymol. 183:111-132(1990).
- [ 2] Stout V., Torres-Cabassa A., Maurizi M.R., Gutnick D., Gottesman S.
- J. Bacteriol. 173:1738-1747(1991).
- [ 3] Kahn D., Ditta G.
- Mol. Microbiol. 5:987-997(1991).
- [ 4] Swift S., Winson M.K., Chan P.F., Bainton N.J., Birdsall M.,
- Reeves P.J., Rees C.E.D., Chhabra S.R., Hill P.J., Throup J.P.,
- Bycroft B.W., Salmond G.P.C., Williams P., Stewart G.S.A.B.
- Mol. Microbiol. 10:511-520(1993).
-