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A family of bacterial proteins has been described [1] which groups transcriptional repressors, sugar kinases and yet uncharacterized open reading frames. This family, known as ROK (Repressor, ORF, Kinase) currently consist of:

• Xylose operon repressor (gene xylR) in Bacillus subtilis, Lactobacillus pentosus and Staphylococcus xylosus.
• N-acetylglucosamine repressor (gene nagC) from Escherichia coli.
• Glucokinase (EC 2.7.1.2) (gene glk) from Streptomyces coelicolor.
• Fructokinase (EC 2.7.1.4) (gene scrK or frk) from Pediococcus pentosaceus, Streptococcus mutans and Zymomonas mobilis.
• Escherichia coli allokinase (EC 2.7.1.55) (gene alsK).
• Escherichia protein mlc.
• Hypothetical Escherichia coli protein yajF and HI0182, the corresponding Haemophilus influenzae protein.
• Hypothetical Escherichia coli protein yhcI and HI0144, the corresponding Haemophilus influenzae protein.
• A hypothetical protein in nagH 5'region from Clostridium perfringens.

The repressor proteins (xylR and nagC) from this family possess a N-terminal region not present in the sugar kinases and which contains an helix-turn-helix DNA-binding motif. The domain common to all these proteins consists of about 300 residues. It is not highly conserved, but we could define a pattern centered on a glycine-rich region in the central part of the domain.

December 2004 / Pattern and text revised.

PROSITE method (with tools and information) covered by this documentation:

ROK, PS01125; ROK family signature  (PATTERN)

Consensus pattern: [LIVM]-x(2)-G-[LIVMFCT]-G-x-[GA]-[LIVMFA]-x(3)-{V}-x(4)-G-x(3,5)-[GATP]-{G}-x-G-[RKH] Sequences known to belong to this class detected by the pattern: ALL, except for mlc Other sequence(s) detected in Swiss-Prot: 5.

• Retrieve an alignment of Swiss-Prot true positive hits:   Clustal format, color, condensed view  / Clustal format, color  / Clustal format, plain text  / Fasta format • Retrieve the sequence logo from the alignment • Taxonomic tree view of all Swiss-Prot/TrEMBL entries matching PS01125 • Retrieve a list of all Swiss-Prot/TrEMBL entries matching PS01125 • Scan Swiss-Prot/TrEMBL entries against PS01125 • view ligand binding statistics

Matching PDB structures: 1XC3 2AA4 2AP1 3LM9 ... [ALL]

1	Authors	Titgemeyer F., Reizer J., Reizer A., Saier M.H. Jr.
	Title	Evolutionary relationships between sugar kinases and transcriptional repressors in bacteria.
	Source	Microbiology 140:2349-2354(1994).
	PubMed ID	7952186

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