The domain within your query sequence starts at position 488 and ends at position 819; the E-value for the HMG-CoA_red domain shown below is 1.3e-148.

ERGVSIRRQLLSTKLAEPSSLQYLPYRDYNYSLVMGACCENVIGYMPIPVGVAGPLCLDG
KEYQVPMATTEGCLVASTNRGCRAISLGGGASSRVLADGMTRGPVVRLPRACDSAEVKTW
LETPEGFAVIKEAFDSTSRFARLQKLHVTMAGRNLYIRFQSRTGDAMGMNMISKGTEKAL
LKLQEFFPDMQILAVSGNYCTDKKPAAINWIEGRGKTVVCEAVIPAKVVREVLKTTTEAM
VDVNINKNLVGSAMAGSIGGYNAHAANIVTAIYIACGQDAAQNVGSSNCITLMEASGPTN
EDLYISCTMPSIEIGTVGGGTNLLPQQACLQV

HMG-CoA_red

HMG-CoA_red
PFAM accession number:PF00368
Interpro abstract (IPR002202):

There are two distinct classes of hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase enzymes: class I consists of eukaryotic and most archaeal enzymes (EC 1.1.1.34), while class II consists of prokaryotic enzymes (EC 1.1.1.88) [(PUBMED:10068515), (PUBMED:15535874)].

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 [(PUBMED:15535874)]. 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 [(PUBMED:10600463)]. 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 [(PUBMED:15028676)]. 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).

GO process:oxidation-reduction process (GO:0055114), coenzyme A metabolic process (GO:0015936)
GO function:coenzyme binding (GO:0050662), hydroxymethylglutaryl-CoA reductase (NADPH) activity (GO:0004420)

This is a PFAM domain. For full annotation and more information, please see the PFAM entry HMG-CoA_red