Structural organization of WrbA in apo- and holoprotein crystals.
Two previously reported holoprotein crystal forms of the flavodoxin-like E. coli protein WrbA, diffracting to 2.6 and 2.0 A resolution, and new crystals of WrbA apoprotein diffracting to 1.85 A, are refined and analysed comparatively through the lens of flavodoxin structures. The results indicate that differences between apo- and holoWrbA crystal structures are manifested on many levels of protein organization as well as in the FMN-binding sites. Evaluation of the influence of crystal contacts by comparison of lattice packing reveals the protein's global response to FMN binding. Structural changes upon cofactor binding are compared with the monomeric flavodoxins. Topologically non-equivalent residues undergo remarkably similar local structural changes upon FMN binding to WrbA or to flavodoxin, despite differences in multimeric organization and residue types at the binding sites. Analysis of the three crystal structures described here, together with flavodoxin structures, rationalizes functional similarities and differences of the WrbAs relative to flavodoxins, leading to a new understanding of the defining features of WrbAs. The results suggest that WrbAs are not a remote and unusual branch of the flavodoxin family as previously thought but rather a central member with unifying structural features.
Wolfova
Julie
J
Institute of Physical Biology, University of South Bohemia, Zamek 136, 37333 Nove Hrady, Czech Republic.
Smatanova
Ivana Kuta
IK
Brynda
Jiri
J
Mesters
Jeroen R
JR
Lapkouski
Mikalai
M
Kuty
Michal
M
Natalello
Antonino
A
Chatterjee
Neal
N
Chern
Sy-Yeu
SY
Ebbel
Erin
E
Ricci
Angela
A
Grandori
Rita
R
Ettrich
Rüdiger
R
Carey
Jannette
J
D017033:Anabaena / Q000737:chemistry; D001059:Apoproteins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry*; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000378:metabolism*; D005486:Flavin Mononucleotide / Q000737:chemistry / Q000378:metabolism; D005418:Flavodoxin / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D055503:Protein Multimerization; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*
D001059:Apoproteins; D029968:Escherichia coli Proteins; D005418:Flavodoxin; D012097:Repressor Proteins; C081759:WrbA protein, E coli; D005486:Flavin Mononucleotide