second protein kinase C conserved region 1 (C1 domain) found in diacylglycerol kinase beta (DAG kinase beta) and similar proteins
Diacylglycerol (DAG) kinase (EC 2.7.1.107) is a lipid kinase that phosphorylates diacylglycerol to form phosphatidic acid. DAG kinase beta, also called 90 kDa diacylglycerol kinase, or diglyceride kinase beta (DGK-beta), exhibits high phosphorylation activity for long-chain diacylglycerols. It is classified as a type I DAG kinase (DGK), containing EF-hand structures that bind Ca(2+) and a recoverin homology domain, in addition to C1 and catalytic domains that are present in all DGKs. As a type I DGK, it is regulated by calcium binding. DAG kinase beta contains two copies of the C1 domain. This model corresponds to the second one. DGK-beta contains typical C1 domains that bind DAG and phorbol esters. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.