PDBsum entry 5kf3

Toxin

PDB id: 5kf3

Contents

Protein chain

234 a.a.

Waters ×165

PDB id:

5kf3

Name:

Toxin

Title:

Truncated hemolysin a from p. Mirabilis y134a at 2.2 angstroms resolution

Structure:

Hemolysin. Chain: a. Engineered: yes

Source:

Proteus mirabilis. Organism_taxid: 584. Gene: hpma. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.20Å R-factor: 0.174 R-free: 0.207

Authors:

W.R.P.Novak,B.Bhattacharyya,T.M.Weaver

Key ref:

W.R.Novak et al. (2017). Proteolysis of truncated hemolysin A yields a stable dimerization interface. Acta Crystallogr F Struct Biol Commun, 73, 138-145. PubMed id: 28291749

Date:

11-Jun-16 Release date: 22-Mar-17

Protein chain

P16466  (HLYA_PROMI) -  Hemolysin from Proteus mirabilis

Seq: 1577 a.a.

Struc: 234 a.a.*

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

Acta Crystallogr F Struct Biol Commun 73:138-145 (2017)

PubMed id: 28291749

Proteolysis of truncated hemolysin A yields a stable dimerization interface.

W.R.Novak, B.Bhattacharyya, D.P.Grilley, T.M.Weaver.

ABSTRACT

Wild-type and variant forms of HpmA265 (truncated hemolysin A) from Proteus mirabilis reveal a right-handed, parallel β-helix capped and flanked by segments of antiparallel β-strands. The low-salt crystal structures form a dimeric structure via the implementation of on-edge main-chain hydrogen bonds donated by residues 243-263 of adjacent monomers. Surprisingly, in the high-salt structures of two variants, Y134A and Q125A-Y134A, a new dimeric interface is formed via main-chain hydrogen bonds donated by residues 203-215 of adjacent monomers, and a previously unobserved tetramer is formed. In addition, an eight-stranded antiparallel β-sheet is formed from the flap regions of crystallographically related monomers in the high-salt structures. This new interface is possible owing to additional proteolysis of these variants after Tyr240. The interface formed in the high-salt crystal forms of hemolysin A variants may mimic the on-edge β-strand positioning used in template-assisted hemolytic activity.