4iu3

<table><tr><td colspan='2'>[[4iu3]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Atcc_19208 Atcc 19208]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IU3 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4IU3 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4iu2|4iu2]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4iu3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4iu3 OCA], [http://pdbe.org/4iu3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4iu3 RCSB], [http://www.ebi.ac.uk/pdbsum/4iu3 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4iu3 ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

The rumen bacterium Ruminococcus flavefaciens produces a highly organized multienzyme cellulosome complex that plays a key role in the degradation of plant cell wall polysaccharides, notably cellulose. The R. flavefaciens cellulosomal system is anchored to the bacterial cell wall through a relatively small ScaE scaffoldin subunit, which bears a single type-IIIe cohesin responsible for the attachment of two major dockerin-containing scaffoldin proteins: ScaB and the cellulose-binding protein CttA. While ScaB recruits the catalytic machinery onto the complex, CttA mediates attachment of the bacterial substrate via its two putative carbohydrate-binding modules (CBMs). In an effort to understand the structural basis for assembly and cell-surface attachment of the cellulosome in R. flavefaciens, we determined the crystal structure of the high-affinity complex (Kd = 20.83 nM) between the ScaE cohesin module (CohE) and its cognate X-dockerin modular dyad (XDoc) from CttA at 1.97-A resolution. The structure reveals an atypical calcium-binding loop containing a 13-residue insert. The results further pinpoint two charged specificity-related residues on the surface of the cohesin module, which are responsible for specific vs. promiscuous cross-strain binding of the dockerin module. In addition, a combined functional role for the three enigmatic dockerin inserts was established, whereby these extraneous segments serve as structural buttresses that reinforce the stalk-like conformation of the X-module, thus segregating its tethered complement of cellulosomal components from the cell surface. The novel structure of the RfCohE-XDoc complex sheds light on divergent dockerin structure and function and provides insight into the specificity features of the type-IIIe cohesin-dockerin interaction.

 

Atypical cohesin-dockerin complex responsible for cell-surface attachment of cellulosomal components: binding fidelity, promiscuity, and structural buttresses.,Salama-Alber O, Jobby MK, Chitayat S, Smith SP, White BA, Shimon LJ, Lamed R, Frolow F, Bayer EA J Biol Chem. 2013 Apr 11. PMID:23580648<ref>PMID:23580648</ref>

 

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<references/>

[[Category: Atcc 19208]]

[[Category: Bayer, E]]

[[Category: Frolow, F]]

[[Category: Salama-Alber, O]]

[[Category: Structural protein]]