1CZU

REFINED STRUCTURES OF OXIDIZED FLAVODOXIN FROM ANACYSTIS NIDULANS

Summary for 1CZU

• Entry DOI: 10.2210/pdb1czu/pdb
• Related: 1CZH 1CZK 1CZL 1CZN 1CZO 1CZR 1CZU 1D03 1D04
• Descriptor: FLAVODOXIN, FLAVIN MONONUCLEOTIDE (3 entities in total)
• Functional Keywords: flavodoxin, fmn binding, redox potential, crystal packing, electron transport
• Biological source: Synechococcus elongatus
• Total number of polymer chains: 1
• Total formula weight: 19112.64

Authors

Drennan, C.L.,Pattridge, K.A.,Weber, C.H.,Metzger, A.L.,Hoover, D.M.,Ludwig, M.L. (deposition date: 1999-09-07, release date: 1999-12-29, Last modification date: 2024-02-07)

Primary citation

Drennan, C.L.,Pattridge, K.A.,Weber, C.H.,Metzger, A.L.,Hoover, D.M.,Ludwig, M.L.
Refined structures of oxidized flavodoxin from Anacystis nidulans.
J.Mol.Biol., 294:711-724, 1999

PubMed Abstract: Flavodoxin from Anacystis nidulans (Synechococcus PCC 7942) was the first member of the flavodoxin family to be characterized, and is the structural prototype for the "long-chain" flavodoxins that have molecular masses of approximately 20 kDa. Crystal structure analyses and refinements of three orthorhombic forms of oxidized A. nidulans flavodoxin are reported, and salient features of the fold and the FMN binding site are compared with other flavodoxins. The structure of form I (wild-type: P212121, a=57.08 A, b=69.24 A, c=45.55 A), determined initially by multiple isomorphous replacement, has been refined to R=0.183 and R(free)=0.211 for data from 10.0 to 1.7 A resolution. Structures of form II (wild-type: P212121, a=60.05 A, b=65.85 A, c=51.36 A) and form III (Asn58Gly: P212121, a=51.30 A, b=59.15 A, c=94.44 A) have been determined by molecular replacement and refined versus data to 2.0 A and 1.85 A, respectively; the R values for forms II and III are 0.147 and 0.150. Changes in the molecular contacts that produce the alternative packings in these crystalline forms are analyzed. Deletion of the Asn side-chain in the mutant Asn58Gly removes an intermolecular stacking interaction and allows the alternative packing found in form III crystals. The functionally important 50's loop of the FMN binding site is less restrained by intermolecular contacts in these crystals but maintains the same conformation as in oxidized wild type protein. The structures reported here provide the starting point for structure-function studies of the reduced states and of mutants, described in the accompanying paper.

PubMed: 10610791
DOI: 10.1006/jmbi.1999.3151

Experimental method

X-RAY DIFFRACTION (2 Å)