<p>It has been shown [<cite idref="PUB00002140"/>, <cite idref="PUB00004930"/>, <cite idref="PUB00001797"/>] that the following carbohydrate and purine kinases are evolutionary related and can be grouped into a single family, which is known [<cite idref="PUB00002140"/>] as the 'pfkB family':</p><ul> <li>Fructokinase (<db_xref db="EC" dbkey="2.7.1.4"/>) (gene scrK).</li><li>6-phosphofructokinase isozyme 2 (<db_xref db="EC" dbkey="2.7.1.11"/>) (phosphofructokinase-2) (gene pfkB). pfkB is a minor phosphofructokinase isozyme in <taxon tax_id="562">Escherichia coli</taxon> and is not evolutionary related to the major isozyme (gene pfkA). Plant 6-phosphofructokinase also belong to this family.</li><li>Ribokinase (<db_xref db="EC" dbkey="2.7.1.15"/>) (gene rbsK).</li><li>Adenosine kinase (<db_xref db="EC" dbkey="2.7.1.20"/>) (gene ADK).</li><li>2-dehydro-3-deoxygluconokinase (<db_xref db="EC" dbkey="2.7.1.45"/>) (gene: kdgK).</li><li>1-phosphofructokinase (<db_xref db="EC" dbkey="2.7.1.56"/>) (fructose 1-phosphate kinase) (gene fruK).</li><li>Inosine-guanosine kinase (<db_xref db="EC" dbkey="2.7.1.73"/>) (gene gsk).</li><li>Tagatose-6-phosphate kinase (<db_xref db="EC" dbkey="2.7.1.144"/>) (phosphotagatokinase) (gene lacC).</li><li>E. coli hypothetical protein yeiC.</li><li>E. coli hypothetical protein yeiI.</li><li>E. coli hypothetical protein yhfQ.</li><li>E. coli hypothetical protein yihV.</li><li>Yeast hypothetical protein YJR105w.</li> </ul><p>All the above kinases are proteins of from 280 to 430 amino acid residues that share a few region of sequence similarity.</p><li>Note: some bacterial fructokinases belong to the ROK family (see <db_xref db="INTERPRO" dbkey="IPR000600"/>).</li> Carbohydrate/puine kinase, PfkB, conserved site