PDBsum entry 4c2f

Hydrolase

PDB id: 4c2f

Contents

Protein chain

434 a.a.

Ligands

ALA-ALA-ALA

ALA-ALA-ALA-ALA-SER-ALA-ALA

Waters ×70

PDB id:

4c2f

Name:

Hydrolase

Title:

Crystal structure of the ctpb r168a mutant present in an active conformation

Structure:

Carboxy-terminal processing protease ctpb. Chain: a. Fragment: residues 44-480. Synonym: c-terminal processing protease, ctpb. Engineered: yes. Mutation: yes. Peptide1. Chain: b. Other_details: peptide co-purified from e. Coli expression.

Source:

Bacillus subtilis subsp. Subtilis str. 168. Organism_taxid: 224308. Expressed in: escherichia coli. Expression_system_taxid: 511693. Escherichia coli. Organism_taxid: 511693. Strain: bl21. Strain: bl21

Resolution:

2.40Å R-factor: 0.215 R-free: 0.265

Authors:

M.Mastny,A.Heuck,R.Kurzbauer,T.Clausen

Key ref:

M.Mastny et al. (2013). CtpB assembles a gated protease tunnel regulating cell-cell signaling during spore formation in Bacillus subtilis. Cell, 155, 647-658. PubMed id: 24243021 DOI: 10.1016/j.cell.2013.09.050

Date:

17-Aug-13 Release date: 04-Dec-13

Protein chain

O35002  (CTPB_BACSU) -  Carboxy-terminal processing protease CtpB from Bacillus subtilis (strain 168)

Seq: 480 a.a.

Struc: 434 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.3.4.21.102 - C-terminal processing peptidase.
• Reaction: The enzyme shows specific recognition of a C-terminal tripeptide, Xaa-Yaa-Zaa, in which Xaa is preferably Ala or Leu, Yaa is preferably Ala or Tyr, and Zaa is preferably Ala, but then cleaves at a variable distance from the C-terminus. A typical cleavage is -Ala-Ala-|-Arg-Ala-Ala-Lys-Glu-Asn-Tyr-Ala-Leu-Ala-Ala. In the plant chloroplast, the enzyme removes the C-terminal extension of the D1 polypeptide of photosystem II.

DOI no: 10.1016/j.cell.2013.09.050

Cell 155:647-658 (2013)

PubMed id: 24243021

CtpB assembles a gated protease tunnel regulating cell-cell signaling during spore formation in Bacillus subtilis.

M.Mastny, A.Heuck, R.Kurzbauer, A.Heiduk, P.Boisguerin, R.Volkmer, M.Ehrmann, C.D.Rodrigues, D.Z.Rudner, T.Clausen.

ABSTRACT

Spore formation in Bacillus subtilis relies on a regulated intramembrane proteolysis (RIP) pathway that synchronizes mother-cell and forespore development. To address the molecular basis of this SpoIV transmembrane signaling, we carried out a structure-function analysis of the activating protease CtpB. Crystal structures reflecting distinct functional states show that CtpB constitutes a ring-like protein scaffold penetrated by two narrow tunnels. Access to the proteolytic sites sequestered within these tunnels is controlled by PDZ domains that rearrange upon substrate binding. Accordingly, CtpB resembles a minimal version of a self-compartmentalizing protease regulated by a unique allosteric mechanism. Moreover, biochemical analysis of the PDZ-gated channel combined with sporulation assays reveal that activation of the SpoIV RIP pathway is induced by the concerted activity of CtpB and a second signaling protease, SpoIVB. This proteolytic mechanism is of broad relevance for cell-cell communication, illustrating how distinct signaling pathways can be integrated into a single RIP module.