Isobutyryl-CoA mutase

Ratnatilleke A, JW Vrijbloed, JA Robinson (1999) Cloning and sequencing of the coenzyme B,2-binding domain of isobutyryl-CoA mutase from Streptomyces cinnamonensis. Reconstitution of mutase activity and characterization of the recombinant enzyme produced in Escherichia coli. J Biol Chem 274 31679-31685. 

COMPUTER ALGORITHMS SOFTWARE ISOBUTYRYL-CoA MUTASE "ISOCALC4,"... 

Isobutyryl-CoA mutase catalyzes the same type of reaction... 

Isoaspartyl group 84 Isobutyraldehyde, tautomerism 45 Isobutyryl-CoA mutase 872 Isocitrate 516s, 686s, 704s... 

About 10 coenzyme B -dependent enzymes are now known (reviewed in References 13,14, and 76 see Table 1) four carbon skeleton mutases (methylmalonyl-CoA mutase (MMCM), glutamate mutase (GM), methylene glu-tarate mutase (MGM), isobutyryl-CoA mutase (ICM) ), diol dehydratase (DD), glycerol dehydratase, ethanol-amine anunonia lyase (EAL), two amino mutases, and Bi2-dependent ribonucleotide reductase. The coenzyme Bi2-dependent enzymes are unevenly distributed in the living world, and MMCM is the only enzyme that is also indispensable in human metabolism. ... 

The reaction of isobutyryl-CoA mutase was found to be similar in principle (Equation (15)). The genes and heterodimeric subunit composition and catalytic properties have been described. ... 

Fig. 4 A, B. Polyketide synthase substrate routes. Potential substrates have been boxed A enzymes performing one enzymatic conversion 1, acetyl-CoA synthetase (alternatively, 1 represents a two enzyme pathway, acetate kinase followed by acetylphosphotransferase) 2, acetyl-CoA carboxylase 3, mal-onyl-CoA decarboxylase 4, malonyl-CoA synthetase B enzymes performing one enzymatic conversion 1, propionyl-CoA synthetase (T, propionate kinase followed by propionylphosphotransferase) 2, propionyl-CoA carboxylase 3, methylmalonyl-CoA decarboxylase 4, methylmalonyl-CoA epimerase 5, methylmalonyl-CoA mutase 6, isobutyryl-CoA mutase...

Vrilbloed JW, Zerbe-Brnkhardt K, Ratnatilleke A, Grubelnik-Leiser A, Robinson JA (1999) Insertional inactivation of methylmalonyl coenzyme A (CoA) mutase and isobutyryl-CoA mutase genes in Streptomyces cinnamonensis-. influence on polyketide antibiotic biosynthesis. J Bacteriol 181 5600 - 5605... 

Besides MMCM and GM, two other coenzyme B -dependent carbon skeleton mutases are known. These are (1) methylene glutarate mutase (MGM) from the anaerobe Eubacterium (Clostridium) barkeri, which catalyzes the equilibration of 2-methylene-glutarate with (R)-3-methylitaconate as part of a degradative path of nicotinic acid [175,199] and (2) isobutyryl-CoA mutase (ICM), which is observed in species of gram-positive bacteria Strep-tomyces and catalyzes the reversible rearrangement of iso-butyryl-CoA and n-butyryl-CoA [177]. The isomerization of iso-butyryl-CoA and n-butyryl-CoA in ICM is relevant in the biosynthesis of polyketide antibiotics [177]. 

---