1nfp
From Proteopedia
STRUCTURAL REFINEMENT OF THE NON-FLUORESCENT FLAVOPROTEIN FROM PHOTOBACTERIUM LEIOGNATHI AT 1.60 ANGSTROMS RESOLUTION
Overview
The crystallographically-determined structure of the non-fluorescent flavoprotein (NFP) from Photobacterium leiognathi, a homolog of the bacterial luciferase subunits, has been refined to a conventional R-factor [formula: see text] of 0.175 using synchrotron data between 10.0 and 1.60 A resolution. The molecular structure is a homodimer of beta/alpha domains, the monomer having structural similarities to (beta alpha)8 barrel proteins. However, one beta-strand and three alpha-helices of a typical (beta alpha)8 domain are not present in the NFP structure. The refined structure of NFP consists of the 228 amino acid polypeptide, 191 water molecules, a sulfate ion, and two flavin mononucleotides (FMNs) each with a covalently-attached myristate (C14 fatty acid). Both flavin adducts are well-ordered and have exceptional electron density for both the FMN and the myristate moieties. Each flavin mononucleotide-myristate adduct is characterized by a stereospecific linkage (the S enantiomer) between C-6 of the flavin isoalloxazine ring and the C-3' atom of the fatty acyl chain. The stereospecific nature of this flavin-fatty acid linkage suggests that it is the result of an enzyme-catalyzed reaction, most likely the bioluminescence reaction itself. The myristate chains are buried from solvent in hydrophobic pockets in the interior of the protein. Four amino acid side-chains of the NFP polypeptide have been modeled with alternate conformations. Five of the protein's seven alpha-helices have classical C-capping boxes. NFP is dimeric and many of the extensive contacts at the dimer interface are mediated by hydrogen-bonded water molecules as well as by hydrophobic interactions. One of the myristate acyl chains sits between NFP monomers and contributes a significant portion of the hydrophobic interactions at the NFP dimer interface.
About this Structure
1NFP is a Single protein structure of sequence from Photobacterium leiognathi. Full crystallographic information is available from OCA.
Reference
Structural refinement of the non-fluorescent flavoprotein from Photobacterium leiognathi at 1.60 A resolution., Moore SA, James MN, J Mol Biol. 1995 May 26;249(1):195-214. PMID:7776372 Page seeded by OCA on Sat May 3 02:28:38 2008
