LIS - Legume Information System
Information about legume traits for crop improvement
CicerMine
v5.1.0.3
Cicer data from the Legume Information System
v5.1.0.3
Cicer data from the Legume Information System
| Type | Family |
| Description | There are two distinct classes of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase enzymes: class I consists of eukaryotic and most archaeal enzymes ( ), while class II consists of prokaryotic enzymes ( ) [ , ].Class I HMG-CoA reductases catalyse the NADP-dependent synthesis of mevalonate from 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA). In vertebrates, membrane-bound HMG-CoA reductase is the rate-limiting enzyme in the biosynthesis of cholesterol and other isoprenoids. In plants, mevalonate is the precursor of all isoprenoid compounds [ ]. The reduction of HMG-CoA to mevalonate is regulated by feedback inhibition by sterols and non-sterol metabolites derived from mevalonate, including cholesterol. In archaea, HMG-CoA reductase is a cytoplasmic enzyme involved in the biosynthesis of the isoprenoids side chains of lipids []. Class I HMG-CoA reductases consist of an N-terminal membrane domain (lacking in archaeal enzymes), and a C-terminal catalytic region. The catalytic region can be subdivided into three domains: an N-domain (N-terminal), a large L-domain, and a small S-domain (inserted within the L-domain). The L-domain binds the substrate, while the S-domain binds NADP.Class II HMG-CoA reductases catalyse the reverse reaction of class I enzymes, namely the NAD-dependent synthesis of HMG-CoA from mevalonate and CoA [ ]. Some bacteria, such as Pseudomonas mevalonii, can use mevalonate as the sole carbon source. Class II enzymes lack a membrane domain. Their catalytic region is structurally related to that of class I enzymes, but it consists of only two domains: a large L-domain and a small S-domain (inserted within the L-domain). As with class I enzymes, the L-domain binds substrate, but the S-domain binds NAD (instead of NADP in class I).This entry represents class II HMG-CoA reductases, as well as some class I enzymes from archaea. This family was built from two class II NAD-dependent enzymes from organisms closely related to Pseudomonas mevalonii, a bacterium that can use mevalonate as its sole carbon source. Some archaeal HMG-CoA reductases were found to be of bacterial origin [ ]. This family is occasionally found together with a thiolase ( ) to form a putative bifunctional acetyl-CoA acetyltransferase/HMG-CoA reductase protein [ ]. |
| Short Name | HMG_CoA_Rdtase_bac-typ |
