Xylose isomerase-like, TIM barrel domain <p>This entry represents a structural motif with a beta/alpha TIM barrel found in several proteins families:</p><p> <ul><li>Endonuclease IV (<db_xref db="EC" dbkey="3.1.21.2"/>), an AP (apurinic/apyrimidinic) endonuclease that primes DNA repair synthesis by cleaving the DNA backbone 5' of AP sites [<cite idref="PUB00017986"/>].</li><li>L-rhamnose isomerase (<db_xref db="EC" dbkey="5.3.1.14"/>), a tetramer of four TIM barrels that catalyses the isomerisation between aldoses and ketoses, such as between L-rhamnose and L-rhamnulose [<cite idref="PUB00035702"/>].</li><li>Xylose isomerase (<db_xref db="EC" dbkey="5.3.1.5"/>), which catalyses the first reaction in the catabolism of D-xylose by converting D-xylose to D-xylulose [<cite idref="PUB00035703"/>].</li><li>Mannonate dehydratase UxuA, which along with mannonate oxidoreductase converts D-fructuronate to 2-keto-3-deoxy-D-gluconate [<cite idref="PUB00035704"/>].</li></ul> </p><p>These proteins share similar, but not identical, metal-binding sites. In addition, xylose isomerase and L-rhamnose isomerase each have additional alpha-helical domains involved in tetramer formation. This entry differs from IPR012307 in having a wider coverage of TIM-barrel protein families.</p>