 |
|
|
 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
153 a.a.
_NA
Key reference
DOI no: 10.1074/jbc.M109558200 J Biol Chem 276:49061-49065 (2001) PubMed id: 11598143
Structure of a family 15 carbohydrate-binding module in complex with xylopentaose. Evidence that xylan binds in an approximate 3-fold helical conformation. L.Szabo, S.Jamal, H.Xie, S.J.Charnock, D.N.Bolam, H.J.Gilbert, G.J.Davies. ABSTRACT
The recycling of photosynthetically fixed carbon by the action of microbial glycoside hydrolases is a key biological process. The consortium of degradative enzymes involved in this process frequently display catalytic modules appended to one or more noncatalytic carbohydrate-binding modules (CBMs). CBMs play a central role in the optimization of the catalytic activity of plant cell wall hydrolases through their binding to specific plant structural polysaccharides. Despite their pivotal role in the biodegradation of plant biomass, the mechanism by which these proteins recognize their target ligands is unclear. This report describes the structure of a xylan-binding CBM (CBM15) in complex with its ligand. This module, derived from Pseudomonas cellulosa xylanase Xyn10C, binds to both soluble xylan and xylooligosaccharides. The three-dimensional crystal structure of CBM15 bound to xylopentaose has been solved by x-ray crystallography to a resolution of 1.6 A. The protein displays a similar beta-jelly roll fold to that observed in many other families of binding-modules. A groove, 20-25 A in length, on the concave surface of one of the beta-sheets presents two tryptophan residues, the faces of which are orientated at approximately 240 degrees to one another. These form-stacking interactions with the n and n+2 sugars of xylopentaose complementing the approximate 3-fold helical structure of this ligand in the binding cleft of CBM15. In four of the five observed binding subsites, the 2' and 3' hydroxyls of the bound ligand are solvent-exposed, providing an explanation for the capacity of this xylan-binding CBM to accommodate the highly decorated xylans found in the plant cell wall.
Selected figure(s)
Figure 1.
Fig. 1. The three-dimensional structure of the P. cellulosa CBM15 in complex with xylopentaose. A displays the overall secondary structure of the protein with the location of bound xylopentaose. B shows the electron density of xylopentaose bound to CBM15. The map shown is a maximum-likelihood/[A] weighted 2F[obs]
F[calc] synthesis (28) calculated at a contour level of ~0.6 electrons/Å2. This figure was made with MOLSCRIPT/BOBSCRIPT (38, 39).
Figure 2.
Fig. 2. Schematic diagram of the interactions of CBM15 with xylopentaose.The above figures are reprinted by permission from the ASBMB: J Biol Chem (2001, 276, 49061-49065) copyright 2001.
Literature references that cite this PDB file's key reference
PubMed id Reference
19682075 C.Christiansen, M.Abou Hachem, S.Janecek, A.Viksø-Nielsen, A.Blennow, and B.Svensson (2009).
The carbohydrate-binding module family 20--diversity, structure, and function.FEBS J, 276, 5006-5029.
19144002 C.Hervé, A.Rogowski, H.J.Gilbert, and J.Paul Knox (2009).
Enzymatic treatments reveal differential capacities for xylan recognition and degradation in primary and secondary plant cell walls.Plant J, 58, 413-422.
16758444 B.Granvogl, V.Reisinger, and L.A.Eichacker (2006).
Mapping the proteome of thylakoid membranes by de novo sequencing of intermembrane peptide domains.Proteomics, 6, 3681-3695.
16537424 L.McCartney, A.W.Blake, J.Flint, D.N.Bolam, A.B.Boraston, H.J.Gilbert, and J.P.Knox (2006).
Differential recognition of plant cell walls by microbial xylan-specific carbohydrate-binding modules.Proc Natl Acad Sci U S A, 103, 4765-4770.
15853815 J.Jänis, J.Hakanpää, N.Hakulinen, F.M.Ibatullin, A.Hoxha, P.J.Derrick, J.Rouvinen, and P.Vainiotalo (2005).
Determination of thioxylo-oligosaccharide binding to family 11 xylanases using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and X-ray crystallography.FEBS J, 272, 2317-2333.
PDB code: 1xnk
12391332 S.J.Charnock, D.N.Bolam, D.Nurizzo, L.Szabó, V.A.McKie, H.J.Gilbert, and G.J.Davies (2002).
Promiscuity in ligand-binding: The three-dimensional structure of a Piromyces carbohydrate-binding module, CBM29-2, in complex with cello- and mannohexaose.Proc Natl Acad Sci U S A, 99, 14077-14082.
PDB codes: 1gwk 1gwl 1gwm
11589704 I.Szabò, F.Rigoni, M.Bianchetti, D.Carbonera, F.Pierantoni, R.Seraglia, A.Segalla, and G.M.Giacometti (2001).
Isolation and characterization of photosystem II subcomplexes from cyanobacteria lacking photosystem I.Eur J Biochem, 268, 5129-5134. The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time. Where a reference describes a PDB structure, the PDB code is shown on the right.
 |