Structural data on the periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli: SAXS and preliminary X-ray crystallography analysis.
The periplasmic aldehyde oxidoreductase PaoABC from Escherichia coli is a molybdenum enzyme involved in detoxification of aldehydes in the cell. It is an example of an αβγ heterotrimeric enzyme of the xanthine oxidase family of enzymes which does not dimerize via its molybdenum cofactor binding domain. In order to structurally characterize PaoABC, X-ray crystallography and small angle X-ray scattering (SAXS) have been carried out. The protein crystallizes in the presence of 20% (w/v) polyethylene glycol 3350 using the hanging-drop vapour diffusion method. Although crystals were initially twinned, several experiments were done to overcome twinning and lowering the crystallization temperature (293 K to 277 K) was the solution to the problem. The non-twinned crystals used to solve the structure diffract X-rays to beyond 1.80 Å and belong to the C2 space group, with cell parameters a = 109.42 Å, b = 78.08 Å, c = 151.77 Å, β = 99.77°, and one molecule in the asymmetric unit. A molecular replacement solution was found for each subunit separately, using several proteins as search models. SAXS data of PaoABC were also collected showing that, in solution, the protein is also an αβγ heterotrimer.
REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal. a.cardoso@campus.fct.unl.pt.
Ana Rita
AR
Otrelo-Cardoso
REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal. marcia.correia@fct.unl.pt.
Márcia Alexandra
MA
da Silva Correia
Institut für Biochemie and Biologie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Golm, Potsdam 14476, Germany. visch@uni-potsdam.de.
Viola
V
Schwuchow
European Molecular Biology Laboratory, Hamburg Outstation, Notkestrasse 85, Hamburg 22607, Germany. svergun@embl-hamburg.de.
Dmitri I
DI
Svergun
REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal. mjr@fct.unl.pt.
Maria João
MJ
Romão
Institut für Biochemie and Biologie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, Golm, Potsdam 14476, Germany. sleim@uni-potsdam.de.
Silke
S
Leimkühler
REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica 2829-516, Portugal. tsss@fct.unl.pt.
Teresa
T
Santos-Silva
D000444:Aldehyde Dehydrogenase / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology*; D019897:Periplasm / Q000201:enzymology*; D011487:Protein Conformation; D053838:Scattering, Small Angle
D000444:Aldehyde Dehydrogenase