PDBsum entry 4kb5

Hydrolase

PDB id: 4kb5

Contents

Protein chain

386 a.a.

Ligands

GOL ×10

Waters ×177

PDB id:

4kb5

Name:

Hydrolase

Title:

Crystal structure of mycp1 from mycobacterium smegmatis

Structure:

Membrane-anchored mycosin mycp1. Chain: a. Fragment: unp residues 24-422. Synonym: peptidase s8 and s53, subtilisin, kexin, sedolisin. Engineered: yes

Source:

Mycobacterium smegmatis. Organism_taxid: 246196. Strain: atcc 700084 / mc(2)155. Gene: msmeg_0083, msmei_0081. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.15Å R-factor: 0.190 R-free: 0.214

Authors:

D.M.Sun,Y.He,C.L.Tian

Key ref:

D.Sun et al. (2013). The putative propeptide of MycP1 in mycobacterial type VII secretion system does not inhibit protease activity but improves protein stability. Protein Cell, 4, 921-931. PubMed id: 24248472 DOI: 10.1007/s13238-013-3089-7

Date:

23-Apr-13 Release date: 05-Feb-14

Protein chain

A0QNL1  (MYCP1_MYCS2) -  Mycosin-1 from Mycolicibacterium smegmatis (strain ATCC 700084 / mc(2)155)

Seq: 449 a.a.

Struc: 386 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.3.4.21.- - ?????

DOI no: 10.1007/s13238-013-3089-7

Protein Cell 4:921-931 (2013)

PubMed id: 24248472

The putative propeptide of MycP1 in mycobacterial type VII secretion system does not inhibit protease activity but improves protein stability.

D.Sun, Q.Liu, Y.He, C.Wang, F.Wu, C.Tian, J.Zang.

ABSTRACT

Mycosin-1 protease (MycP1) is a serine protease anchored to the inner membrane of Mycobacterium tuberculosis, and is essential in virulence factor secretion through the ESX-1 type VII secretion system (T7SS). Bacterial physiology studies demonstrated that MycP1 plays a dual role in the regulation of ESX-1 secretion and virulence, primarily through cleavage of its secretion substrate EspB. MycP1 contains a putative N-terminal inhibitory propeptide and a catalytic triad of Asp-His-Ser, classic hallmarks of a subtilase family serine protease. The MycP1 propeptide was previously reported to be initially inactive and activated after prolonged incubation. In this study, we have determined crystal structures of MycP1 with (MycP1²⁴⁻⁴²²) and without (MycP1⁶³⁻⁴²²) the propeptide, and conducted EspB cleavage assays using the two proteins. Very high structural similarity was observed in the two crystal structures. Interestingly, protease assays demonstrated positive EspB cleavage for both proteins, indicating that the putative propeptide does not inhibit protease activity. Molecular dynamic simulations showed higher rigidity in regions guarding the entrance to the catalytic site in MycP1²⁴⁻⁴²² than in MycP1⁶³⁻⁴²², suggesting that the putative propeptide might contribute to the conformational stability of the active site cleft and surrounding regions.