RING finger motif

Parkin is a ubiquitin ligase encoded by a gene affected in autosomal recessive juvenile parkinsonism (AR-JP). This gene is located on chromosome 6 and encodes a protein of 465 amino acid residues with moderate similarity to ubiquitin at the amino terminus and a RING-finger motif at the carboxy terminus. 

A RING finger motif (see Section 2.6.1) and ubiquitin ligase activity have been identified in BRCA1. The purpose of the E3 activity of BRCA1 is unknown. 

Other Protein-Protein Interaction Motifs in RING finger Proteins... 

The most extensively studied TRIAD is Parkin, shown schematically in Figure 4.5A. The N-terminus contains a region homologous to ubiquitin called the ubiq-uitin domain (UbD), which interacts directly with proteasomes. The C-terminus contains two RING fingers (Rl, R2) separated by a cysteine-rich in-between i ING (IBR) region. This TRIAD motif mediates E3 activity and interacts with molecular chaperones. The last three amino acids of Parkin interact with a PDZ domain and possibly function to anchor Parkin to lipid microdomains. 

Boedallo, j. and D. H. Wole, A RING-H2 finger motif is essential For the function of Der3/Hrdl in endoplasmic reticulum associated protein degradation in the yeast Saccharomyces cerevisiae. FEBS Lett, 1999, 448(2-3), 244-8. 

Moynihan, T. P., et al., The ubiquitin-conjugating enzymes UbcH7 and UbcH8 interact with RING finger/IBR motif-containing domains of HHARI and H7-AP1./... 

Capili, a. D., et al., Structure of the C-terminal RING Finger from a RING-IBR-RING/TRIAD Motif Reveals a Novel Zinc-binding Domain Distinct from a RING. / Mol Biol,... 

Pringa, E., Martinez-Noel, G., Muller, U., and Harbers, K. Interaction of the ring finger-related U-box motif of a nuclear dot protein with ubiquitin-conjugatmg enzymes. 

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