1SCU

THE CRYSTAL STRUCTURE OF SUCCINYL-COA SYNTHETASE FROM ESCHERICHIA COLI AT 2.5 ANGSTROMS RESOLUTION

Summary for 1SCU

• Entry DOI: 10.2210/pdb1scu/pdb
• Descriptor: SUCCINYL-COA SYNTHETASE, ALPHA SUBUNIT, SUCCINYL-COA SYNTHETASE, BETA SUBUNIT, COENZYME A, ... (4 entities in total)
• Functional Keywords: ligase (atp-binding)
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 143928.49

Authors

Wolodko, W.T.,Fraser, M.E.,James, M.N.G.,Bridger, W.A. (deposition date: 1993-11-18, release date: 1995-04-20, Last modification date: 2025-03-26)

Primary citation

Wolodko, W.T.,Fraser, M.E.,James, M.N.,Bridger, W.A.
The crystal structure of succinyl-CoA synthetase from Escherichia coli at 2.5-A resolution.
J.Biol.Chem., 269:10883-10890, 1994

PubMed Abstract: The x-ray crystal structure of succinyl-CoA synthetase (SCS) from Escherichia coli has been determined by the method of multiple isomorphous replacement to a resolution of 2.5 A. Crystals of SCS are tetragonal with a space group of P4(3)22 and unit cell dimensions of a = b = 98.47 A and c = 400.6 A. One molecule of SCS (142 kDa) is contained in the asymmetric unit. The current model has been refined to a conventional R factor of 21.6% with root mean square deviations from ideal stereochemistry of 0.022 A for bond lengths and 3.25 degrees for bond angles. The quaternary organization of the E. coli enzyme is an alpha 2 beta 2 heterotetramer. In this tetramer, the alpha-subunits interact only with the beta-subunits, whereas the beta-subunits interact to form the dimer of alpha beta-dimers. The two active site pockets are located at regions of contact between alpha- and beta-subunits. One molecule of coenzyme A is bound to each alpha-subunit at a typical nucleotide-binding motif, and His-246 of each alpha-subunit is phosphorylated. This phosphohistidine, a catalytic intermediate, is stabilized by two helix dipoles (the "power" helices), one from each of the two subunit types. A short segment of the beta-subunit from one alpha beta-dimer is in close proximity to the CoA-binding site of the other alpha beta-dimer, providing a possible rationale for the overall tetrameric structure.

PubMed: 8144675

Experimental method

X-RAY DIFFRACTION (2.5 Å)