PDBsum entry 5ej1

Metal binding protein

PDB id: 5ej1

Contents

Protein chains

721 a.a.

657 a.a.

Ligands

UNK-UNK-UNK-UNK

UNK-UNK-UNK

BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC-BGC

C2E ×2

XP5 ×2

3PE ×2

PDB id:

5ej1

Name:

Metal binding protein

Title:

Pre-translocation state of bacterial cellulose synthase

Structure:

Putative cellulose synthase. Chain: a. Fragment: unp residues 13-740. Engineered: yes. Putative cellulose synthase. Chain: b. Fragment: unp residues 52-720. Engineered: yes. Poly(unk).

Source:

Rhodobacter sphaeroides (strain atcc 17023 / 2.4.1 / ncib 8253 / dsm 158). Organism_taxid: 272943. Strain: atcc 17023 / 2.4.1 / ncib 8253 / dsm 158. Gene: rsp_0333. Expressed in: escherichia coli. Expression_system_taxid: 562. Gene: rsp_0332. Rhodobacter sphaeroides.

Resolution:

3.40Å R-factor: 0.235 R-free: 0.277

Authors:

J.L.W.Moragn,J.Zimmer

Key ref:

J.L.Morgan et al. (2016). Observing cellulose biosynthesis and membrane translocation in crystallo. Nature, 531, 329-334. PubMed id: 26958837 DOI: 10.1038/nature16966

Date:

30-Oct-15 Release date: 30-Mar-16

Protein chain

Q3J125  (Q3J125_RHOS4) -  Cellulose synthase catalytic subunit [UDP-forming] from Cereibacter sphaeroides (strain ATCC 17023 / DSM 158 / JCM 6121 / CCUG 31486 / LMG 2827 / NBRC 12203 / NCIMB 8253 / ATH 2.4.1.)

Seq: 788 a.a.

Struc: 721 a.a.

Protein chain

Q3J126  (Q3J126_RHOS4) -  Cyclic di-GMP-binding protein from Cereibacter sphaeroides (strain ATCC 17023 / DSM 158 / JCM 6121 / CCUG 31486 / LMG 2827 / NBRC 12203 / NCIMB 8253 / ATH 2.4.1.)

Seq: 725 a.a.

Struc: 657 a.a.

Enzyme reactions

• Enzyme class: Chain A: E.C.2.4.1.12 - cellulose synthase (UDP-forming).
• Reaction: [(1->4)-beta-D-glucosyl](n) + UDP-alpha-D-glucose = [(1->4)-beta-D- glucosyl](n+1) + UDP + H⁺

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

Added reference

DOI no: 10.1038/nature16966

Nature 531:329-334 (2016)

PubMed id: 26958837

Observing cellulose biosynthesis and membrane translocation in crystallo.

J.L.Morgan, J.T.McNamara, M.Fischer, J.Rich, H.M.Chen, S.G.Withers, J.Zimmer.

ABSTRACT

Many biopolymers, including polysaccharides, must be translocated across at least one membrane to reach their site of biological function. Cellulose is a linear glucose polymer synthesized and secreted by a membrane-integrated cellulose synthase. Here, in crystallo enzymology with the catalytically active bacterial cellulose synthase BcsA-BcsB complex reveals structural snapshots of a complete cellulose biosynthesis cycle, from substrate binding to polymer translocation. Substrate- and product-bound structures of BcsA provide the basis for substrate recognition and demonstrate the stepwise elongation of cellulose. Furthermore, the structural snapshots show that BcsA translocates cellulose via a ratcheting mechanism involving a 'finger helix' that contacts the polymer's terminal glucose. Cooperating with BcsA's gating loop, the finger helix moves 'up' and 'down' in response to substrate binding and polymer elongation, respectively, thereby pushing the elongated polymer into BcsA's transmembrane channel. This mechanism is validated experimentally by tethering BcsA's finger helix, which inhibits polymer translocation but not elongation.