Crystal structure of p44, a constitutively active splice variant of visual arrestin

J Mol Biol. 2012 Mar 9;416(5):611-8. doi: 10.1016/j.jmb.2012.01.028. Epub 2012 Jan 27.


Visual arrestin specifically binds to photoactivated and phosphorylated rhodopsin and inactivates phototransduction. In contrast, the p44 splice variant can terminate phototransduction by binding to nonphosphorylated light-activated rhodopsin. Here we report the crystal structure of bovine p44 at a resolution of 1.85 Å. Compared to native arrestin, the p44 structure reveals significant differences in regions crucial for receptor binding, namely flexible loop V-VI and polar core regions. Additionally, electrostatic potential is remarkably positive on the N-domain and the C-domain. The p44 structure represents an active conformation that serves as a model to explain the 'constitutive activity' found in arrestin variants.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arrestin / chemistry*
  • Arrestin / genetics
  • Arrestin / metabolism
  • Cattle
  • Crystallography, X-Ray / methods
  • Genetic Variation
  • Light Signal Transduction
  • Models, Molecular
  • Phosphorylation
  • Protein Binding
  • Protein Structure, Tertiary / genetics
  • RNA Splicing
  • Rhodopsin / metabolism
  • Static Electricity


  • Arrestin
  • Rhodopsin

Associated data

  • PDB/3UGU
  • PDB/3UGX