Crystal structures of TM0549 and NE1324--two orthologs of E. coli AHAS isozyme III small regulatory subunit.
Crystal structures of two orthologs of the regulatory subunit of acetohydroxyacid synthase III (AHAS, EC 2.2.1.6) from Thermotoga maritima (TM0549) and Nitrosomonas europea (NE1324) were determined by single-wavelength anomalous diffraction methods with the use of selenomethionine derivatives at 2.3 A and 2.5 A, respectively. TM0549 and NE1324 share the same fold, and in both proteins the polypeptide chain contains two separate domains of a similar size. Each protein contains a C-terminal domain with ferredoxin-type fold and an N-terminal ACT domain, of which the latter is characteristic for several proteins involved in amino acid metabolism. The ferredoxin domain is stabilized by a calcium ion in the crystal structure of NE1324 and by a Mg(H2O)(6)2+ ion in TM0549. Both TM0549 and NE1324 form dimeric assemblies in the crystal lattice.
Petkowski
Janusz J
JJ
Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville 22908, USA.
Chruszcz
Maksymilian
M
Zimmerman
Matthew D
MD
Zheng
Heping
H
Skarina
Tatiana
T
Onopriyenko
Olena
O
Cymborowski
Marcin T
MT
Koclega
Katarzyna D
KD
Savchenko
Alexei
A
Edwards
Aled
A
Minor
Wladek
W
D000095:Acetolactate Synthase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D020124:Thermotoga maritima / Q000201:enzymology* / Q000235:genetics
D001426:Bacterial Proteins; D007527:Isoenzymes; D001120:Arginine; D000095:Acetolactate Synthase; D002118:Calcium