Amylase
From Proteopedia
| Line 8: | Line 8: | ||
==Structure== | ==Structure== | ||
BSTA comprises of a single polypeptide chain. This chain is folded into three domains A, B and C. These domains are generally recognized on α-amylase enzymes. The A domain constitutes the core structure, with a (β/α)barrel.The B domain consists of a sheet of four anti-parallel β-strands with a pair of anti-parallel β-strands. Long loops are observed between the β-strands. Located within the B domain is the binding site for Ca2+- Na+- Ca2+.Domain C consisting of eight β-strands assembles into a globular unit forming a Greek key motif. It also holds the third Ca2+ binding site in association with domain A.Positioned on the C-terminal side of the β-strands of the (β/ α)8barrel in domain A, is the active site. The catalytic residues involved in the active site are Asp234, Glu264, and Asp331, for BSTA. The residues are identical to other α-amylases, yet there are positional differences which reflect the flexible nature of catalytic resides. | BSTA comprises of a single polypeptide chain. This chain is folded into three domains A, B and C. These domains are generally recognized on α-amylase enzymes. The A domain constitutes the core structure, with a (β/α)barrel.The B domain consists of a sheet of four anti-parallel β-strands with a pair of anti-parallel β-strands. Long loops are observed between the β-strands. Located within the B domain is the binding site for Ca2+- Na+- Ca2+.Domain C consisting of eight β-strands assembles into a globular unit forming a Greek key motif. It also holds the third Ca2+ binding site in association with domain A.Positioned on the C-terminal side of the β-strands of the (β/ α)8barrel in domain A, is the active site. The catalytic residues involved in the active site are Asp234, Glu264, and Asp331, for BSTA. The residues are identical to other α-amylases, yet there are positional differences which reflect the flexible nature of catalytic resides. | ||
| - | CaI, and CaII found at the interface of domain A and C, and CaIII with Na found in the interior of domain B, constitute the metal ion binding sites. CaI is consistent in all α-amylases, however there are differences between the linear trio of CaII, CaIII and Na in other enzymes. | + | CaI, and CaII found at the interface of domain A and C, and CaIII with Na found in the interior of domain B, constitute the metal ion binding sites. CaI is consistent in all α-amylases, however there are differences between the linear trio of CaII, CaIII and Na in other enzymes.CaIII acts as a bridge between two loops, one from Aα6 of domain A, and between Cβ1 and Cβ2 of domain C. |
==Function== | ==Function== | ||
adasdasd | adasdasd | ||
Revision as of 01:02, 26 March 2010
| Please do NOT make changes to this Sandbox until after April 23, 2010. Sandboxes 151-200 are reserved until then for use by the Chemistry 307 class at UNBC taught by Prof. Andrea Gorrell. |
Contents |
Introduction
α-Amylase is an enzyme that acts as a catalyst for the hydrolysis of alpha-linked polysaccharides into α-anomeric products.[1]The enzyme comes from a variety of sources, each with different characteristics.
Structure
BSTA comprises of a single polypeptide chain. This chain is folded into three domains A, B and C. These domains are generally recognized on α-amylase enzymes. The A domain constitutes the core structure, with a (β/α)barrel.The B domain consists of a sheet of four anti-parallel β-strands with a pair of anti-parallel β-strands. Long loops are observed between the β-strands. Located within the B domain is the binding site for Ca2+- Na+- Ca2+.Domain C consisting of eight β-strands assembles into a globular unit forming a Greek key motif. It also holds the third Ca2+ binding site in association with domain A.Positioned on the C-terminal side of the β-strands of the (β/ α)8barrel in domain A, is the active site. The catalytic residues involved in the active site are Asp234, Glu264, and Asp331, for BSTA. The residues are identical to other α-amylases, yet there are positional differences which reflect the flexible nature of catalytic resides. CaI, and CaII found at the interface of domain A and C, and CaIII with Na found in the interior of domain B, constitute the metal ion binding sites. CaI is consistent in all α-amylases, however there are differences between the linear trio of CaII, CaIII and Na in other enzymes.CaIII acts as a bridge between two loops, one from Aα6 of domain A, and between Cβ1 and Cβ2 of domain C.
Function
adasdasd
Digestion
texttext [2]
References
- ↑ Suvd D, Fujimoto Z, Takase K, Matsumura M, Mizuno H. Crystal structure of Bacillus stearothermophilus alpha-amylase: possible factors determining the thermostability. J Biochem. 2001 Mar;129(3):461-8. PMID:11226887
- ↑ Suvd D, Fujimoto Z, Takase K, Matsumura M, Mizuno H. Crystal structure of Bacillus stearothermophilus alpha-amylase: possible factors determining the thermostability. J Biochem. 2001 Mar;129(3):461-8. PMID:11226887
Proteopedia Page Contributors and Editors (what is this?)
Shane Riley, Michal Harel, Joel L. Sussman, Randi Woodbeck, Jaime Prilusky, Alexander Berchansky, Ann Taylor, Andrea Gorrell, David Canner
