second protein kinase C conserved region 1 (C1 domain) found in novel protein kinase C (nPKC) theta, delta, and similar proteins
PKCs are classified into three groups (classical, atypical, and novel) depending on their mode of activation and the structural characteristics of their regulatory domain. nPKCs are calcium-independent, but require DAG (1,2-diacylglycerol) and phosphatidylserine (PS) for activity. PKC-theta is selectively expressed in T-cells and plays an important and non-redundant role in several aspects of T-cell biology. PKC-delta plays a role in cell cycle regulation and programmed cell death in many cell types. Members of this family contain two copies of C1 domain. This model corresponds to the second one. 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.