1XRB

S-adenosylmethionine synthetase (MAT, ATP: L-methionine S-adenosyltransferase, E.C.2.5.1.6) in which MET residues are replaced with selenomethionine residues (MSE)

Summary for 1XRB

• Entry DOI: 10.2210/pdb1xrb/pdb
• Descriptor: S-ADENOSYLMETHIONINE SYNTHETASE, PHOSPHATE ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: methyltransferase, transferase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P04384
• Total number of polymer chains: 1
• Total formula weight: 42606.11

Authors

Takusagawa, F.,Kamitori, S.,Misaki, S.,Markham, G.D. (deposition date: 1995-10-26, release date: 1996-03-08, Last modification date: 2024-10-23)

Primary citation

Takusagawa, F.,Kamitori, S.,Misaki, S.,Markham, G.D.
Crystal structure of S-adenosylmethionine synthetase.
J.Biol.Chem., 271:136-147, 1996

PubMed Abstract: The structure of S-adenosylmethionine synthetase (MAT, ATP:L-methionine S-adenosyltransferase, EC 2.5.1.6.) from Escherichia coli has been determined at 3.0 A resolution by multiple isomorphous replacement using a uranium derivative and the selenomethionine form of the enzyme (SeMAT). The SeMAT data (9 selenomethionine residues out of 383 amino acid residues) have been found to have a sufficient phasing power to determine the structure of the 42,000 molecular weight protein by combining them with the other heavy atom derivative data (multiple isomorphous replacement). The enzyme consists of four identical subunits; two subunits form a spherical tight dimer, and pairs of these dimers form a peanut-shaped tetrameric enzyme. Each pair dimer has two active sites which are located between the subunits. Each subunit consists of three domains that are related to each other by pseudo-3-fold symmetry. The essential divalent (Mg2+/Co2+) and monovalent (K+) metal ions and one of the product, Pi ions, were found in the active site from three separate structures.

PubMed: 8550549
DOI: 10.1074/jbc.271.1.136

Experimental method

X-RAY DIFFRACTION (3 Å)