Crystal structure of p44, a constitutively active splice variant of visual arrestin.
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.
Institute of Complex Systems, ICS-6: Structural Biochemistry, Forschungszentrum Jülich, 52425 Jülich, Germany.
Joachim
J
Granzin
Anneliese
A
Cousin
Moritz
M
Weirauch
Ramona
R
Schlesinger
Georg
G
Büldt
Renu
R
Batra-Safferling
D000818:Animals; D019393:Arrestin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D018360:Crystallography, X-Ray / Q000379:methods; D014644:Genetic Variation; D055537:Light Signal Transduction; D008958:Models, Molecular; D010766:Phosphorylation; D011485:Protein Binding; D017434:Protein Structure, Tertiary / Q000235:genetics; D012326:RNA Splicing; D012243:Rhodopsin / Q000378:metabolism; D055672:Static Electricity
D019393:Arrestin; D012243:Rhodopsin