PDBsum entry 5cxx

Hydrolase

PDB id: 5cxx

Contents

Protein chains

272 a.a.

Ligands

FER ×3

SO4 ×3

GOL ×11

Waters ×864

PDB id:

5cxx

Name:

Hydrolase

Title:

Structure of a ce1 ferulic acid esterase, amce1/fae1a, from anaeromyces mucronatus in complex with ferulic acid

Structure:

Ferulic acid esterase, amce1/fae1a. Chain: a, b, c. Engineered: yes

Source:

Anaeromyces mucronatus. Organism_taxid: 994854. Gene: fae1a. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

1.55Å R-factor: 0.142 R-free: 0.160

Authors:

R.J.Gruninger,D.W.Abbott

Key ref:

R.J.Gruninger et al. (2016). Contributions of a unique β-clamp to substrate recognition illuminates the molecular basis of exolysis in ferulic acid esterases. Biochem J, 473, 839-849. PubMed id: 27026397 DOI: 10.1042/BJ20151153

Date:

29-Jul-15 Release date: 27-Apr-16

Protein chains

F2YCB6  (F2YCB6_9FUNG) -  Fae1A from Anaeromyces mucronatus

Seq: 275 a.a.

Struc: 272 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.1.73 - feruloyl esterase.
• Reaction: feruloyl-polysaccharide + H2O = ferulate + polysaccharide

feruloyl-polysaccharide + H2O = ferulate (Bound ligand (Het Group name = FER) corresponds exactly) + polysaccharide

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

Added reference

DOI no: 10.1042/BJ20151153

Biochem J 473:839-849 (2016)

PubMed id: 27026397

Contributions of a unique β-clamp to substrate recognition illuminates the molecular basis of exolysis in ferulic acid esterases.

R.J.Gruninger, C.Cote, T.A.McAllister, D.W.Abbott.

ABSTRACT

Lignocellulosic biomass is a promising renewable resource; however, deconstruction of this material is still the rate-limiting step. Major obstacles in the biocatalytic turnover of lignocellulose are ester-linked decorations that prevent access to primary structural polysaccharides. Enzymes targeting these esters represent promising biotools for increasing bioconversion efficiency. Ruminant livestock are unique in their ability to degrade lignocellulose through the action of their gut microbiome. The anaerobic fungi (phylum Neocallimastigomycota) are key members of this ecosystem that express a large repertoire of carbohydrate-active enzymes (CAZymes) with little sequence identity with characterized CAZymes [Lombard, Golaconda, Drula, Coutinho and Henrissat (2014) Nucleic Acids Res. 42: , D490-D495]. We have identified a carbohydrate esterase family 1 (CE1) ferulic acid esterase (FAE) belonging toAnaeromyces mucronatus(AmCE1/Fae1a), and determined its X-ray structure in both the presence [1.55 Å (1 Å=0.1 nm)] and absence (1.60 Å) of ferulic acid. AmCE1 adopts an α/β-hydrolase fold that is structurally conserved with bacterial FAEs, and possesses a unique loop, termed the β-clamp, that encloses the ligand. Isothermal titration calorimetry reveals that substrate binding is driven by enthalpic contributions, which overcomes a large entropic penalty. A comparative analysis of AmCE1 with related enzymes has uncovered the apparent structural basis for differential FAE activities targeting cross-linking ferulic acid conjugates compared with terminal decorations. Based on comparisons to structurally characterized FAEs, we propose that the β-clamp may define the structural basis of exolytic activities in FAEs. This provides a structure-based tool for predicting exolysis and endolysis in CE1. These insights hold promise for rationally identifying enzymes tailored for bioconversion of biomass with variations in cell wall composition.