This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1rh8
From Proteopedia
|
Three-dimensional structure of the calcium-free Piccolo C2A-domain
Overview
C2 domains are widespread Ca2+-binding modules. The active zone protein, Piccolo (also known as Aczonin) contains an unusual C2A domain that, exhibits a low affinity for Ca2+, a Ca2+-induced conformational change and, Ca2+-dependent dimerization. We show here that removal of a nine-residue, sequence by alternative splicing increases the Ca2+ affinity, abolishes, the conformational change and abrogates dimerization of the Piccolo C2A, domain. The NMR structure of the Ca2+-free long variant provides a, structural basis for these different properties of the two splice forms, showing that the nine-residue sequence forms a beta-strand otherwise, occupied by a nonspliced sequence. Consequently, Ca2+-binding to the long, Piccolo C2A domain requires a marked rearrangement of secondary structure, that cannot occur for the short variant. These results reveal a novel, mechanism of action of C2 domains and uncover a structural principle that, may underlie the alteration of protein function by short alternatively, spliced sequences.
About this Structure
1RH8 is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
A conformational switch in the Piccolo C2A domain regulated by alternative splicing., Garcia J, Gerber SH, Sugita S, Sudhof TC, Rizo J, Nat Struct Mol Biol. 2004 Jan;11(1):45-53. Epub 2003 Dec 29. PMID:14718922
Page seeded by OCA on Wed Nov 21 01:35:50 2007
