1b3u

Publication Abstract from PubMed

The PR65/A subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit, generating functionally diverse heterotrimers. Mutations of the beta isoform of PR65 are associated with lung and colon tumors. The crystal structure of the PR65/Aalpha subunit, at 2.3 A resolution, reveals the conformation of its 15 tandemly repeated HEAT sequences, degenerate motifs of approximately 39 amino acids present in a variety of proteins, including huntingtin and importin beta. Individual motifs are composed of a pair of antiparallel alpha helices that assemble in a mainly linear, repetitive fashion to form an elongated molecule characterized by a double layer of alpha helices. Left-handed rotations at three interrepeat interfaces generate a novel left-hand superhelical conformation. The protein interaction interface is formed from the intrarepeat turns that are aligned to form a continuous ridge.

The structure of the protein phosphatase 2A PR65/A subunit reveals the conformation of its 15 tandemly repeated HEAT motifs.,Groves MR, Hanlon N, Turowski P, Hemmings BA, Barford D Cell. 1999 Jan 8;96(1):99-110. PMID:9989501^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.