1agm: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1agm.gif|left|200px]] | [[Image:1agm.gif|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_1agm", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
| | --> | ||
| | {{STRUCTURE_1agm| PDB=1agm | SCENE= }} | ||
}} | |||
'''REFINED STRUCTURE FOR THE COMPLEX OF ACARBOSE WITH GLUCOAMYLASE FROM ASPERGILLUS AWAMORI VAR. X100 TO 2.4 ANGSTROMS RESOLUTION''' | '''REFINED STRUCTURE FOR THE COMPLEX OF ACARBOSE WITH GLUCOAMYLASE FROM ASPERGILLUS AWAMORI VAR. X100 TO 2.4 ANGSTROMS RESOLUTION''' | ||
| Line 29: | Line 26: | ||
[[Category: Firsov, L M.]] | [[Category: Firsov, L M.]] | ||
[[Category: Honzatko, R B.]] | [[Category: Honzatko, R B.]] | ||
[[Category: | [[Category: Hydrolase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 10:14:36 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 10:14, 2 May 2008
REFINED STRUCTURE FOR THE COMPLEX OF ACARBOSE WITH GLUCOAMYLASE FROM ASPERGILLUS AWAMORI VAR. X100 TO 2.4 ANGSTROMS RESOLUTION
OverviewOverview
The three-dimensional structure of the pseudotetrasaccharide acarbose complexed with glucoamylase II(471) from Aspergillus awamori var. X100 has been determined to 2.4-A resolution. The model includes residues corresponding to 1-471 of glucoamylase I from Aspergillus niger, a single molecule of bound acarbose, and 535 sites for water molecules. The crystallographic R factor from refinement is 0.124, and the root-mean-squared deviation in bond distances is 0.013 A. Electron density for a single molecule of bound acarbose defines what may be the first four subsites in the binding of extended maltooligosaccharides. Hydrogen bonds between acarbose and the enzyme involve Arg54, Asp55, Arg305, carbonyl177, main chain amide121, Glu179, Glu180, and carbonyl179. Glu179 forms a salt link to the imino linkage between the first and second residues of acarbose. This buried salt link probably contributes significantly to the unusually tight association (Kd approximately 10(-12) M) of acarbose with glucoamylase. In addition, a significant hydrophobic contact between the third residue of acarbose and the side chain of Trp120 distorts the three-center angle of the glucosidic linkage between the second and third residues of acarbose. A water molecule (water500) hydrogen bonds to Glu400 and the 6-hydroxyl of the valienamine moiety of acarbose and is at an approximate distance of 3.7 A from the "anomeric" carbon of the inhibitor. The relevance of the acarbose-glucoamylase complex to the mechanism of enzymic hydrolysis of oligosaccharides is discussed.
About this StructureAbout this Structure
1AGM is a Single protein structure of sequence from Aspergillus awamori. Full crystallographic information is available from OCA.
ReferenceReference
Refined structure for the complex of acarbose with glucoamylase from Aspergillus awamori var. X100 to 2.4-A resolution., Aleshin AE, Firsov LM, Honzatko RB, J Biol Chem. 1994 Jun 3;269(22):15631-9. PMID:8195212 Page seeded by OCA on Fri May 2 10:14:36 2008