Mahoganoid protein (BAB27816): 494 amino acids containing a C3HC4 RING finger domain (underlined). Amino acid comparison of mahoganoid RING domain with Smart00184 (c-Cbl) and other proteins that have E3 ubiquitin-protein ligase activity (33), suggesting a general function of this domain. Human (KIAA0544), D. melanogaster (AAF48305), and C. elegans (CAA94116) homologues of mouse mahoganoid have the conserved C3HC4 RING finger. Conserved amino acids are bold. *The conserved cysteine and histidine residues found in all C3HC4 RING finger domains (34).