A novel protein fold and extreme domain swapping in the dimeric TorD chaperone from Shewanella massilia.
TorD is the cytoplasmic chaperone involved in the maturation of the molybdoenzyme TorA prior to the translocation of the folded protein into the periplasm. The X-ray structure at 2.4 A resolution of the TorD dimer reveals extreme domain swapping between the two subunits. The all-helical architecture of the globular domains within the intertwined molecular dimer shows no similarity with known protein structures. According to sequence similarities, this new fold probably represents the architecture of the chaperones associated with the bacterial DMSO/TMAO reductases and also that of proteins of yet unknown functions. The occurrence of multiple oligomeric forms and the chaperone activity of both monomeric and dimeric TorD raise questions about the possible biological role of domain swapping in this protein.
Tranier
Samuel
S
Groupe de Cristallographie Biologique, Institut de Pharmacologie et Biologie Structurale, 205 route de Narbonne, 31077, Toulouse Cedex, France.
Iobbi-Nivol
Chantal
C
Birck
Catherine
C
Ilbert
Marianne
M
Mortier-Barrière
Isabelle
I
Méjean
Vincent
V
Samama
Jean-Pierre
JP
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D018832:Molecular Chaperones / Q000737:chemistry* / Q000378:metabolism*; D005810:Multigene Family; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D020592:Shewanella / Q000737:chemistry* / Q000378:metabolism
D001426:Bacterial Proteins; D018832:Molecular Chaperones