Solution NMR and X-ray crystal structures of membrane-associated Lipoprotein-17 domain reveal a novel fold.

ABSTRACT: The conserved Lipoprotein-17 domain of membrane-associated protein Q9PRA0_UREPA from Ureaplasma parvum was selected for structure determination by the Northeast Structural Genomics Consortium, as part of the Protein Structure Initiative's program on structure-function analysis of protein domains from large domain sequence families lacking structural representatives. The 100-residue Lipoprotein-17 domain is a "domain of unknown function" (DUF) that is a member of Pfam protein family PF04200, a large domain family for which no members have characterized biochemical functions. The three-dimensional structure of the Lipoprotein-17 domain of protein Q9PRA0_UREPA was determined by both solution NMR and by X-ray crystallography at 2.5 Å. The two structures are in good agreement with each other. The domain structure features three ?-helices, ?1 through ?3, and five ?-strands. Strands ?1/?2, ?3/?4, ?4/?5 are anti-parallel to each other. Strands ?1and ?2 are orthogonal to strands ?3, ?4, ?5, while helix ?3 is formed between the strands ?3 and ?4. One-turn helix ?2 is formed between the strands ?1 and ?2, while helix ?1 occurs in the N-terminal polypeptide segment. Searches of the Protein Data Bank do not identify any other protein with significant structural similarity to Lipoprotein-17 domain of Q9PRA0_UREPA, indicating that it is a novel protein fold.

SUBMITTER: Mani R 

PROVIDER: S-EPMC3636556 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature