PDBsum entry 4zm3

Transferase

PDB id: 4zm3

Contents

Protein chains

389 a.a.

Ligands

PLP ×4

PGE

PEG ×3

Waters ×348

PDB id:

4zm3

Name:

Transferase

Title:

Crystal structure of plp-dependent 3-aminobenzoate synthase pctv wild- type

Structure:

Aminotransferase. Chain: a, b, c, d. Synonym: glutamate-1-semialdehyde aminotransferase-like protein. Engineered: yes

Source:

Streptomyces pactum. Organism_taxid: 68249. Gene: pctv, ptmt. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.27Å R-factor: 0.182 R-free: 0.222

Authors:

A.Hirayama,A.Miyanaga,F.Kudo,T.Eguchi

Key ref:

A.Hirayama et al. (2015). Mechanism-Based Trapping of the Quinonoid Intermediate by Using the K276R Mutant of PLP-Dependent 3-Aminobenzoate Synthase PctV in the Biosynthesis of Pactamycin. Chembiochem, 16, 2484-2490. PubMed id: 26426567 DOI: 10.1002/cbic.201500426

Date:

02-May-15 Release date: 14-Oct-15

Protein chains

A8R0K5  (A8R0K5_9ACTN) -  Aminotransferase from Streptomyces pactum

Seq: 444 a.a.

Struc: 389 a.a.

DOI no: 10.1002/cbic.201500426

Chembiochem 16:2484-2490 (2015)

PubMed id: 26426567

Mechanism-Based Trapping of the Quinonoid Intermediate by Using the K276R Mutant of PLP-Dependent 3-Aminobenzoate Synthase PctV in the Biosynthesis of Pactamycin.

A.Hirayama, A.Miyanaga, F.Kudo, T.Eguchi.

ABSTRACT

Mutational analysis of the pyridoxal 5'-phosphate (PLP)-dependent enzyme PctV was carried out to elucidate the multi-step reaction mechanism for the formation of 3-aminobenzoate (3-ABA) from 3-dehydroshikimate (3-DSA). Introduction of mutation K276R led to the accumulation of a quinonoid intermediate with an absorption maximum at 580 nm after the reaction of pyridoxamine 5'-phosphate (PMP) with 3-DSA. The chemical structure of this intermediate was supported by X-ray crystallographic analysis of the complex formed between the K276R mutant and the quinonoid intermediate. These results clearly show that a quinonoid intermediate is involved in the formation of 3-ABA. They also indicate that Lys276 (in the active site of PctV) plays multiple roles, including acid/base catalysis during the dehydration reaction of the quinonoid intermediate.