PDBsum entry 4m7g

Hydrolase

PDB id: 4m7g

Contents

Protein chain

223 a.a.

Waters ×353

PDB id:

4m7g

Name:

Hydrolase

Title:

Streptomyces erythraeus trypsin

Structure:

Trypsin-like protease. Chain: a. Fragment: unp residues 43-272. Engineered: yes

Source:

Saccharopolyspora erythraea. Organism_taxid: 1836. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

0.81Å R-factor: 0.112 R-free: 0.120

Authors:

E.Blankenship,K.Vukoti,M.Miyagi,D.T.Lodowski

Key ref:

E.Blankenship et al. (2014). Conformational flexibility in the catalytic triad revealed by the high-resolution crystal structure of Streptomyces erythraeus trypsin in an unliganded state. Acta Crystallogr D Biol Crystallogr, 70, 833-840. PubMed id: 24598752 DOI: 10.1107/S1399004713033658

Date:

12-Aug-13 Release date: 12-Mar-14

Protein chain

P24664  (TRYP_SACER) -  Trypsin from Saccharopolyspora erythraea

Seq: 227 a.a.

Struc: 223 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.4.21.4 - trypsin.
• Reaction: Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa.

DOI no: 10.1107/S1399004713033658

Acta Crystallogr D Biol Crystallogr 70:833-840 (2014)

PubMed id: 24598752

Conformational flexibility in the catalytic triad revealed by the high-resolution crystal structure of Streptomyces erythraeus trypsin in an unliganded state.

E.Blankenship, K.Vukoti, M.Miyagi, D.T.Lodowski.

ABSTRACT

With more than 500 crystal structures determined, serine proteases make up greater than one-third of all proteases structurally examined to date, making them among the best biochemically and structurally characterized enzymes. Despite the numerous crystallographic and biochemical studies of trypsin and related serine proteases, there are still considerable shortcomings in the understanding of their catalytic mechanism. Streptomyces erythraeus trypsin (SET) does not exhibit autolysis and crystallizes readily at physiological pH; hence, it is well suited for structural studies aimed at extending the understanding of the catalytic mechanism of serine proteases. While X-ray crystallographic structures of this enzyme have been reported, no coordinates have ever been made available in the Protein Data Bank. Based on this, and observations on the extreme stability and unique properties of this particular trypsin, it was decided to crystallize it and determine its structure. Here, the first sub-angstrom resolution structure of an unmodified, unliganded trypsin crystallized at physiological pH is reported. Detailed structural analysis reveals the geometry and structural rigidity of the catalytic triad in the unoccupied active site and comparison to related serine proteases provides a context for interpretation of biochemical studies of catalytic mechanism and activity.