PDBsum entry 4hpp

Ligase

PDB id: 4hpp

Contents

Protein chain

426 a.a.

Ligands

GLU

Metals

_MG

_CA

Waters ×69

PDB id:

4hpp

Name:

Ligase

Title:

Crystal structure of novel glutamine synthase homolog

Structure:

Probable glutamine synthetase. Chain: a. Engineered: yes

Source:

Pseudomonas aeruginosa. Organism_taxid: 208964. Strain: atcc 15692 / pao1 / 1c / prs 101 / lmg 12228. Gene: pa5508. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.50Å R-factor: 0.209 R-free: 0.292

Authors:

J.E.Ladner,V.Atanasova,Z.Dolezelova,J.F.Parsons

Key ref:

J.E.Ladner et al. (2012). Structure and activity of PA5508, a hexameric glutamine synthetase homologue. Biochemistry, 51, 10121-10123. PubMed id: 23234431

Date:

24-Oct-12 Release date: 26-Dec-12

Protein chain

Q9HT65  (Q9HT65_PSEAE) -  Probable glutamine synthetase from Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1)

Seq: 443 a.a.

Struc: 426 a.a.

Enzyme reactions

• Enzyme class: E.C.6.3.1.11 - glutamate--putrescine ligase.
• Reaction: putrescine + L-glutamate + ATP = gamma-L-glutamylputrescine + ADP + phosphate + H⁺

putrescine + L-glutamate (Bound ligand (Het Group name = GLU) corresponds exactly) + ATP = gamma-L-glutamylputrescine + ADP + phosphate + H(+)

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

reference

Biochemistry 51:10121-10123 (2012)

PubMed id: 23234431

Structure and activity of PA5508, a hexameric glutamine synthetase homologue.

J.E.Ladner, V.Atanasova, Z.Dolezelova, J.F.Parsons.

ABSTRACT

The structure of PA5508 from Pseudomonas aeruginosa, a glutamine synthetase (GS) homologue, has been determined at 2.5 Å. Surprisingly, PA5508 forms single hexameric rings rather than the stacked double rings that are characteristic of GS. The C-terminal helical thong motif that links GS rings is present in PA5508; however, it is folded back toward the core of its own polypeptide, preventing it from interacting with a second ring. Interestingly, PA5508 displays a clear preference for aromatic amine substrates. Unique aspects of the structure illustrate how the enzyme is able to catalyze reactions involving bulky amines rather than ammonia.