RINGFingerDomänen

RING Finger Domänen are a class of highly conserved protein motifs found in eukaryotes. They are characterized by a specific arrangement of cysteine and histidine residues that coordinate zinc ions. This zinc coordination forms a compact, cross-brace structure, giving the domain its name. The canonical RING finger motif typically consists of Cys3HisCys2Cys3 or Cys2HisCys4 residues. While the core structure is conserved, variations exist.

The primary function of RING finger domains is their role in protein-protein interactions. They are often found as part of larger proteins involved in diverse cellular processes, including DNA repair, transcriptional regulation, cell cycle control, and apoptosis. Many RING finger proteins act as E3 ubiquitin ligases or components of E3 ubiquitin ligase complexes. In this capacity, they mediate the transfer of ubiquitin from an E2 conjugating enzyme to a target substrate protein. This ubiquitination can lead to protein degradation, altered protein activity, or changes in protein localization.

The precise role of a RING finger domain within a larger protein is often determined by its surrounding amino acid sequence and its specific interaction partners. Through their ability to mediate ubiquitination and other protein interactions, RING finger domains are critical regulators of cellular signaling and function. Mutations or dysregulation of RING finger proteins can have significant implications for cellular health and are implicated in various diseases, including cancer.