2d05: Difference between revisions

From Proteopedia
Jump to navigationJump to search
OCA (talk | contribs)
No edit summary
OCA (talk | contribs)
No edit summary
Line 1: Line 1:
[[Image:2d05.gif|left|200px]]
{{Seed}}
[[Image:2d05.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_2d05|  PDB=2d05  |  SCENE=  }}  
{{STRUCTURE_2d05|  PDB=2d05  |  SCENE=  }}  


'''Chitosanase From Bacillus circulans mutant K218P'''
===Chitosanase From Bacillus circulans mutant K218P===




==Overview==
<!--  
To identify the amino acids responsible for the substrate binding of chitosanase from Bacillus circulans MH-K1 (MH-K1 chitosanase), Tyr148 and Lys218 of the chitosanase were mutated to serine and proline, respectively, and the mutated chitosanases were characterized. The enzymatic activities of Y148S and K218P were found to be 12.5% and 0.16% of the wild type, respectively. When the (GlcN)3 binding ability to the chitosanase was evaluated by fluorescence spectroscopy and thermal unfolding experiments, the binding abilities of both mutant enzymes were markedly reduced as compared with the wild type enzyme. The affinity of the enzyme for the trisaccharide decreased by 1.0 kcal/mol of binding free energy for Y148S, and 3.7 kcal/mol for K218P. The crystal structure of K218P revealed that Pro218 forms a cis-peptide bond and that the state of the flexible loop containing the 218th residue is considerably affected by the mutation. Thus, we conclude that the flexible loop containing Lys218 plays an important role in substrate binding, and that the role of Tyr148 is less critical, but still important, due to a stacking interaction or hydrogen bond.
The line below this paragraph, {{ABSTRACT_PUBMED_16272568}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 16272568 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_16272568}}


==About this Structure==
==About this Structure==
Line 20: Line 24:
==Reference==
==Reference==
Bacillus circulans MH-K1 chitosanase: amino acid residues responsible for substrate binding., Fukamizo T, Amano S, Yamaguchi K, Yoshikawa T, Katsumi T, Saito J, Suzuki M, Miki K, Nagata Y, Ando A, J Biochem. 2005 Nov;138(5):563-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16272568 16272568]
Bacillus circulans MH-K1 chitosanase: amino acid residues responsible for substrate binding., Fukamizo T, Amano S, Yamaguchi K, Yoshikawa T, Katsumi T, Saito J, Suzuki M, Miki K, Nagata Y, Ando A, J Biochem. 2005 Nov;138(5):563-9. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16272568 16272568]
Crystal structure of chitosanase from Bacillus circulans MH-K1 at 1.6-A resolution and its substrate recognition mechanism., Saito J, Kita A, Higuchi Y, Nagata Y, Ando A, Miki K, J Biol Chem. 1999 Oct 22;274(43):30818-25. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/10521473 10521473]
Crystallization and preliminary X-ray crystallographic analysis of chitosanase from Bacillus circulans MH-K1., Saito JI, Nagata Y, Ando A, Kita A, Miki K, Acta Crystallogr D Biol Crystallogr. 1995 Sep 1;51(Pt 5):856-7. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15299827 15299827]
[[Category: Bacillus circulans]]
[[Category: Bacillus circulans]]
[[Category: Chitosanase]]
[[Category: Chitosanase]]
Line 35: Line 43:
[[Category: Chitosan degradation]]
[[Category: Chitosan degradation]]
[[Category: Hydrolase]]
[[Category: Hydrolase]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 23:27:16 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 11:50:51 2008''