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/IolB family | |||||||||
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![]() 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 | ||||||||
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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.[1] KduI has a TIM-barrel fold.[2]
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.[3] Members of this family possess a Cupin like structure.
References
edit- ^ 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.