1. PARKER, L.L. AND HALL, B.G.
Characterisation and nucleotide sequence of the cryptic cel operon of
Escherichia coli K12.
GENETICS 124(3) 455-471 (1990).
2. FRANK, D.W. AND IGLEWSKI, B.H.
Cloning and sequence analysis of a transregulatory locus required for
exoenzyme-s synthesis in Pseudomonas aeruginosa.
J.BACTERIOL. 173(20) 6460-6468 (1991).
3. STEELE, M.I., LORENZ, D., HATTER, K., PARKS, A. AND SOKATCH, J.R.
Characterisation of the MMSAB operon of Pseudomonas aeruginosa PAO
encoding methylmalonate-semialdehyde dehydrogenase and 3-hydroxyisobutyrate
J.BIOL.CHEM. 267(19) 13585-13592 (1992).
4. WU, J. AND WEISS, B.
Two divergently transcribed genes, soxR and soxS, control a superoxide
response regulon of Escherichia coli.
J.BACTERIOL. 173(9) 2864-2871 (1991).
Numerous bacterial transcription regulatory proteins bind DNA via a
helix-turn-helix (HTH) motif. These proteins are very diverse, but for
convenience may be grouped into subfamilies on the basis of sequence
similarity. One such family groups together a range of proteins, including
aadA, appY, aracC, celD, envY, exsA, fapR, melR, mmsR, rhaR, rhaS, rns,
soxS, tetD, virF and xylS [1-4]. Although the sequences belonging to this
family differ somewhat in length, in each case the HTH motif is situated
towards the C-terminus.
HTHARAC is a 2-element fingerprint that provides a signature for the araC
bacterial regulatory proteins. The fingerprint was derived from an initial
alignment of 7 sequences: the motifs completely encompass the region
encoded by PROSITE pattern HTH_ARAC_FAMILY (PS00041), which includes a
conserved region 30 residues after the DNA-binding domain. Four iterations
on OWL21.1 were required to reach convergence, at which point a true set
comprising 42 sequences was identified.
An update on SPTR37_9f identified a true set of 119 sequences.