Structure of SAICAR synthase from Thermotoga maritima at 2.2 angstroms reveals an unusual covalent dimer.Zhang, R., Skarina, T., Evdokimova, E., Edwards, A., Savchenko, A., Laskowski, R., Cuff, M.E., Joachimiak, A.
(2006) Acta Crystallogr Sect F Struct Biol Cryst Commun 62: 335-339
- PubMed: 16582479
- DOI: https://doi.org/10.1107/S1744309106009651
- Primary Citation of Related Structures:
- PubMed Abstract:
As a part of a structural genomics program, the 2.2 angstroms resolution crystal structure of the PurC gene product from Thermotoga maritima has been solved. This 26.2 kDa protein belongs to the phophoribosylaminoimidazole-succinocarboxamide or SAICAR synthase family of enzymes, the members of which are involved in de novo purine biosynthesis. SAICAR synthase can be divided into three subdomains: two alpha+beta regions exhibiting structural homology with ATP-binding proteins and a carboxy-terminal subdomain of two alpha-helices. The asymmetric unit contains two copies of the protein which are covalently linked by a disulfide bond between Cys126(A) and Cys126(B). This 230-amino-acid protein exhibits high structural homology with SAICAR synthase from baker's yeast. The protein structure is described and compared with that of the ATP-SAICAR synthase complex from yeast.
Biosciences Division, Midwest Center for Structural Genomics, Structural Biology Center, Argonne National Laboratory, Argonne, IL 60439, USA.