PDBsum entry 6b7k

Hydrolase

PDB id: 6b7k

Contents

Protein chains

290 a.a.

Metals

_CA ×8

Waters ×98

PDB id:

6b7k

Name:

Hydrolase

Title:

Gh43 endo-arabinanase from bacillus licheniformis

Structure:

Endo-alpha-(1->5)-l-arabinanase. Chain: a, b, c, d. Engineered: yes

Source:

Bacillus licheniformis (strain atcc 14580 / dsm 13 / jcm 2505 / nbrc 12200 / ncimb 9375 / nrrl nrs-1264 / gibson 46). Organism_taxid: 279010. Strain: atcc 14580 / dsm 13 / jcm 2505 / nbrc 12200 / ncimb 9375 / nrrl nrs-1264 / gibson 46. Gene: abna, bl00353. Expressed in: escherichia coli 'bl21-gold(de3)plyss ag'. Expression_system_taxid: 866768

Resolution:

2.55Å R-factor: 0.232 R-free: 0.274

Authors:

E.G.S.Farro,A.S.Nascimento

Key ref:

E.G.S.Farro et al. (2018). GH43 endo-arabinanase from Bacillus licheniformis: Structure, activity and unexpected synergistic effect on cellulose enzymatic hydrolysis. Int J Biol Macromol, 117, 7. PubMed id: 29800670 DOI: 10.1016/j.ijbiomac.2018.05.157

Date:

04-Oct-17 Release date: 13-Jun-18

Protein chains

Q65GB9  (Q65GB9_BACLD) -  Endo-alpha-(1->5)-L-arabinanase from Bacillus licheniformis (strain ATCC 14580 / DSM 13 / JCM 2505 / CCUG 7422 / NBRC 12200 / NCIMB 9375 / NCTC 10341 / NRRL NRS-1264 / Gibson 46)

Seq: 320 a.a.

Struc: 290 a.a.

Enzyme reactions

• Enzyme class: E.C.3.2.1.99 - arabinan endo-1,5-alpha-L-arabinosidase.
• Reaction: Endohydrolysis of 1,5-alpha-L-arabinofuranosidic linkages in 1,5-arabinans.

DOI no: 10.1016/j.ijbiomac.2018.05.157

Int J Biol Macromol 117:7 (2018)

PubMed id: 29800670

GH43 endo-arabinanase from Bacillus licheniformis: Structure, activity and unexpected synergistic effect on cellulose enzymatic hydrolysis.

E.G.S.Farro, A.E.T.Leite, I.A.Silva, J.G.Filgueiras, E.R.de Azevedo, I.Polikarpov, A.S.Nascimento.

ABSTRACT

The hydrolysis of the plant biomass provides many interesting opportunities for the generation of building blocks for the green chemistry industrial applications. An important progress has been made for the hydrolysis of the cellulosic component of the biomass while, for the hemicellulosic components, the advances are less straightforward. Here, we describe the cloning, expression and biochemical and structural characterization of BlAbn1, a GH43 arabinanase from Bacillus licheniformis. This enzyme is selective for linear arabinan and efficiently hydrolyzes this substrate, with a specific activity of 127 U/mg. The enzyme has optimal conditions for activity at pH 8.0 and 45 °C and its activity is only partially dependent of a bound calcium ion since 70% of the maximal activity is preserved even when 1 mM EDTA is added to the reaction medium. BlAbn1 crystal structure revealed a typical GH43 fold and narrow active site, which explains the selectivity for linear substrates. Unexpectedly, the enzyme showed a synergic effect with the commercial cocktail Accellerase 1500 on cellulose hydrolysis. Scanning Electron Microscopy, Solid-State NMR and relaxometry data indicate that the enzyme weakens the interaction between cellulose fibers in filter paper, thus providing an increased access to the cellulases of the cocktail.