PDBsum entry 4dbc

Transferase

PDB id: 4dbc

Contents

Protein chain

396 a.a.

Ligands

SO4 ×4

EDO

3QP

Waters ×447

PDB id:

4dbc

Name:

Transferase

Title:

Substrate activation in aspartate aminotransferase

Structure:

Aspartate aminotransferase. Chain: a. Synonym: aspat, transaminase a. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 83333. Strain: k12. Expressed in: escherichia coli. Expression_system_taxid: 83333.

Resolution:

1.50Å R-factor: 0.170 R-free: 0.194

Authors:

M.D.Toney,A.J.Fisher,W.R.Griswold

Key ref:

W.R.Griswold et al. (2012). Ground-state electronic destabilization via hyperconjugation in aspartate aminotransferase. J Am Chem Soc, 134, 8436-8438. PubMed id: 22551424

Date:

14-Jan-12 Release date: 05-Dec-12

Protein chain

P00509  (AAT_ECOLI) -  Aspartate aminotransferase from Escherichia coli (strain K12)

Seq: 396 a.a.

Struc: 396 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.2.6.1.1 - aspartate transaminase.
• Reaction: L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate

L-aspartate + 2-oxoglutarate = oxaloacetate + L-glutamate (Bound ligand (Het Group name = EDO) matches with 44.44% similarity)

• Cofactor: Pyridoxal 5'-phosphate

Pyridoxal 5'-phosphate (Bound ligand (Het Group name = 3QP) matches with 53.85% similarity)

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

J Am Chem Soc 134:8436-8438 (2012)

PubMed id: 22551424

Ground-state electronic destabilization via hyperconjugation in aspartate aminotransferase.

W.R.Griswold, J.N.Castro, A.J.Fisher, M.D.Toney.

ABSTRACT

Binding isotope effects for l-aspartate reacting with the inactive K258A mutant of PLP-dependent aspartate aminotransferase to give a stable external aldimine intermediate are reported. They provide direct evidence for electronic ground-state destabilization via hyperconjugation. The smaller equilibrium isotope effect with deazaPLP-reconstituted K258A indicates that the pyridine nitrogen plays an important role in labilizing the Cα-H bond.