This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.


Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.


3bcd

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
(New page: 200px <!-- The line below this paragraph, containing "STRUCTURE_3bcd", creates the "Structure Box" on the page. You may change the PDB parameter (which sets the PD...)
Line 1: Line 1:
-
[[Image:3bcd.jpg|left|200px]]
+
{{Seed}}
 +
[[Image:3bcd.png|left|200px]]
<!--
<!--
Line 9: Line 10:
{{STRUCTURE_3bcd| PDB=3bcd | SCENE= }}
{{STRUCTURE_3bcd| PDB=3bcd | SCENE= }}
-
'''Alpha-amylase B in complex with maltotetraose and alpha-cyclodextrin'''
+
===Alpha-amylase B in complex with maltotetraose and alpha-cyclodextrin===
-
==Overview==
+
<!--
-
The gene for a membrane-bound, halophilic, and thermostable alpha-amylase, AmyB, from Halothermothrix orenii was cloned and sequenced. The crystal structure shows that, in addition to the typical domain organization of family 13 glycoside hydrolases, AmyB carries an additional N-terminal domain (N domain) that forms a large groove--the N-C groove--some 30 A away from the active site. The structure of AmyB with the inhibitor acarbose at 1.35 A resolution shows that a nonasaccharide has been synthesized through successive transglycosylation reactions of acarbose. Unexpectedly, in a complex of wild-type AmyB with alpha-cyclodextrin and maltoheptaose at 2.2 A resolution, a maltotetraose molecule is bound in subsites -1 to +3, spanning the cleavage point at -1/+1, with the -1 glucosyl residue present as a (2)S(o) skew boat. This wild-type AmyB complex was obtained in the presence of a large excess of substrate, a condition under which it is possible to capture Michaelis complexes, which may explain the observed binding across -1/+1 and ring distortion. We observe three methionine side chains that serve as "binding platforms" for glucosyl rings in AmyB, a seemingly rare occurrence in carbohydrate-binding proteins. The structures and results from the biochemical characterization of AmyB and AmyB lacking the N domain show that the N domain increases binding of the enzyme to raw starch. Furthermore, theoretical modeling suggests that the N-C groove can accommodate, spatially and chemically, large substrates such as A-starch.
+
The line below this paragraph, {{ABSTRACT_PUBMED_18387632}}, adds the Publication Abstract to the page
 +
(as it appears on PubMed at http://www.pubmed.gov), where 18387632 is the PubMed ID number.
 +
-->
 +
{{ABSTRACT_PUBMED_18387632}}
==About this Structure==
==About this Structure==
Line 36: Line 40:
[[Category: Raw starch binding]]
[[Category: Raw starch binding]]
[[Category: Thermostable]]
[[Category: Thermostable]]
-
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Apr 24 09:48:13 2008''
+
 
 +
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 04:56:18 2008''

Revision as of 01:56, 29 July 2008

Template:STRUCTURE 3bcd

Alpha-amylase B in complex with maltotetraose and alpha-cyclodextrin

Template:ABSTRACT PUBMED 18387632

About this Structure

3BCD is a Single protein structure of sequence from Halothermothrix orenii. Full crystallographic information is available from OCA.

Reference

Crystal structure of the polyextremophilic alpha-amylase AmyB from Halothermothrix orenii: details of a productive enzyme-substrate complex and an N domain with a role in binding raw starch., Tan TC, Mijts BN, Swaminathan K, Patel BK, Divne C, J Mol Biol. 2008 May 9;378(4):850-68. Epub 2008 Feb 29. PMID:18387632

Page seeded by OCA on Tue Jul 29 04:56:18 2008

Proteopedia Page Contributors and Editors (what is this?)

OCA

Personal tools