The domain within your query sequence starts at position 80 and ends at position 373; the E-value for the SQHop_cyclase_N domain shown below is 2.4e-47.



PFAM accession number:PF13249
Interpro abstract (IPR032697):

Several enzymes catalyse mechanistically related reactions which involve the highly complex cyclic rearrangement of squalene or its 2,3 oxide. Squalene cyclase (SQCY) and 2,3-oxidosqualene cyclase (OSQCY) are integral membrane proteins that catalyse a cationic cyclization cascade converting linear triterpenes to fused ring compounds [ (PUBMED:11027983) (PUBMED:9295270) ]. Lanosterol synthase ( EC ) (oxidosqualene--lanosterol cyclase) catalyses the cyclization of (S)-2,3-epoxysqualene to lanosterol, the initial precursor of cholesterol, steroid hormones and vitamin D in vertebrates and of ergosterol in fungi (gene ERG7). Cycloartenol synthase ( EC ) (2,3-epoxysqualene--cycloartenol cyclase), is a plant enzyme that catalyses the cyclization of (S)-2,3-epoxysqualene to cycloartenol [ (PUBMED:9519404) ], and hopene synthase ( EC 5.4.99 ) (squalene--hopene cyclase), is a bacterial enzyme that catalyses the cyclization of squalene into hopene or diplopterol, a key step in hopanoid (triterpenoid) metabolism [ (PUBMED:9931258) (PUBMED:2253626) ]. These enzymes are evolutionary related [ (PUBMED:7505443) ] proteins of about 70 to 85kDa and have an alpha 6 - alpha 6 barrel fold. Deletion of a single glycine residue of Alicyclobacillus acidocaldarius SQCY alters its substrate specificity into that of eukaryotic OSQCY [ (PUBMED:15593147) ]. Both enzymes have a second minor domain, which forms an alpha-alpha barrel that is inserted into the major domain.

This entry represents the N-terminal domain of squalene cyclases [ (PUBMED:9931258) (PUBMED:12747780) ].

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