| KduI/IolB family | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of 4-deoxy-1-threo-5-hexosulose-uronate ketol-isomerase from enterococcus faecalis | |||||||||
| Identifiers | |||||||||
| Symbol | KduI | ||||||||
| Pfam | PF04962 | ||||||||
| Pfam clan | CL0029 | ||||||||
| InterPro | IPR021120 | ||||||||
| |||||||||
In molecular biology, the KduI/IolB isomerase family is a family of isomerase enzymes that includes 4-deoxy-L-threo-5-hexosulose-uronate ketol-isomerase (5-keto 4-deoxyuronate isomerase) (KduI) and 5-deoxy-glucuronate isomerase (5DG isomerase) (IolB).
KduI is involved in pectin degradation by free-living soil bacteria that use pectin as a carbon source, breaking it down to 2-keto-3-deoxygluconate, which can ultimately be converted to pyruvate. KduI catalyses the fourth step in pectin degradation, namely the interconversion of 5-keto-4-deoxyuronate and 2,5-diketo-3-dexoygluconate. KduI has a TIM-barrel fold.
This family also includes several bacterial Myo-inositol catabolism proteins, such as IolB, which is encoded by the inositol operon (iolABCDEFGHIJ) in Bacillus subtilis. IolB is involved in myo-inositol catabolism. Glucose repression of the iol operon induced by inositol is exerted through catabolite repression mediated by CcpA and the iol induction system mediated by IolR. Members of this family possess a Cupin like structure.
References
- Condemine G, Robert-Baudouy J (September 1991). "Analysis of an Erwinia chrysanthemi gene cluster involved in pectin degradation". Molecular Microbiology. 5 (9): 2191–202. doi:10.1111/j.1365-2958.1991.tb02149.x. PMID 1766386.
- Crowther RL, Georgiadis MM (November 2005). "The crystal structure of 5-keto-4-deoxyuronate isomerase from Escherichia coli". Proteins. 61 (3): 680–4. doi:10.1002/prot.20598. PMID 16152643.
- Miwa Y, Fujita Y (October 2001). "Involvement of two distinct catabolite-responsive elements in catabolite repression of the Bacillus subtilis myo-inositol (iol) operon". Journal of Bacteriology. 183 (20): 5877–84. doi:10.1128/JB.183.20.5877-5884.2001. PMC 99665. PMID 11566986.