Modified RING finger, H2 subclass (C3H3C2-type), found in WD repeat-containing protein mio and its homologs
This subfamily contains Mio, WDR24, WDR59, and their counterparts Sea4, Sea2, and Sea3 from yeast, respectively. Mio/Sea4, Sea2/WDR24, and Sea3/WDR59 are components of the GATOR2 complex, which also includes another two subunits, Seh1and Sec13. GATOR2 and GATOR1, which is composed of three subunits, DEPDC5, Nprl2, and Nprl3, form the Rag-interacting complex GATOR (GAP Activity Towards Rags). Inhibition of GATOR1 subunits makes mTORC1 signaling resistant to amino acid deprivation. In contrast, inhibition of GATOR2 subunits suppresses mTORC1 signaling and GATOR2 negatively regulates DEPDC5. All subfamily members contain an N-terminal WD40 domain and a C-terminal RING-H2 finger with an unusual arrangement of zinc-coordinating residues. The cysteines and histidines in the RING-H2 finger are arranged as a modified C3H3C2-type, rather than the canonical C3H2C3-type.
Conserved feature residue pattern:C C C H H [CH] C C
Evidence:
Comment:based on the structures of other RING-H2 fingers with bound zinc
Comment:some members contain a modified RING-H2 finger (C3H3C2-type), while others contain the canonical C3H2C3-type H2 finger
Comment:C3H2C3-type RING-H2 finger consensus motif: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-H-X2-C-X(4-48)-C-X2-C, where X is any amino acid and the number of X residues varies in different fingers
Comment:A RING finger typically binds two zinc atoms, with its Cys and/or His side chains in a unique "cross-brace" arrangement.
Jiyao W et al.(2023). "The conserved domain database in 2023.",