1mac

<table><tr><td colspan='2'>[[1mac]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/"aerobacillus_macerans"_(schardinger_1905)_donker_1926 "aerobacillus macerans" (schardinger 1905) donker 1926]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MAC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MAC FirstGlance]. <br>

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

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Licheninase Licheninase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.73 3.2.1.73] </span></td></tr>

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== Publication Abstract from PubMed ==

In beta-glucans those beta-1,4 glycosidic bonds which are adjacent to beta-1,3 bonds are cleaved by endo-1,3-1,4-beta-glucanases (beta-glucanases). Here, the relationship between structure and activity of the beta-glucanase of Bacillus macerans is studied by x-ray crystallography and site-directed mutagenesis of active site residues. Crystal structure analysis at 2.3-A resolution reveals a jelly-roll protein structure with a deep active site channel harboring the amino acid residues Trp101, Glu103, Asp105, and Glu107 as in the hybrid Bacillus beta-glucanase H(A16-M) (Keitel, T., Simon, O., Borriss, R., and Heinemann, U. (1993) Proc. Natl. Acad. Sci. U.S.A. 90, 5287-5291). Different mutant proteins with substitutions in these residues are generated by site-directed mutagenesis, isolated, and characterized. Compared with the wild-type enzyme their activity is reduced to less than 1%. Several mutants with isosteric substitutions in Glu103 and Glu107 are completely inactive, suggesting a direct role of these residues in glycosyl bond hydrolysis. The kinetic properties of mutant beta-glucanases and the crystal structure of the wild-type enzyme are consistent with a mechanism where Glu103 and Glu107 are the catalytic amino acid residues responsible for cleavage of the beta-1,4 glycosidic bond within the substrate molecule.

Crystal structure and site-directed mutagenesis of Bacillus macerans endo-1,3-1,4-beta-glucanase.,Hahn M, Olsen O, Politz O, Borriss R, Heinemann U J Biol Chem. 1995 Feb 17;270(7):3081-8. PMID:7852389<ref>PMID:7852389</ref>

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

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== References ==

<references/>

[[Category: Licheninase]]

[[Category: Hahn, M]]

[[Category: Heinemann, U]]