Structure of PDB 1qi4 Chain A

Receptor sequence

>1qi4A (length=418) Species: 316 (Stutzerimonas stutzeri)

DQAGKSPNAVRYHGGDEIILQGFHWNVVREAPNDWYNILRQQAATIAADG
FSAIWMPVPWRDFSSWSDGSKSGGGEGYFWHDFNKNGRYGSDAQLRQAAS
ALGGAGVKVLYDVVPNHMNRGYPDKEINLPAGQGFWRNDCADPGNYPNDC
DDGDRFIGGDADLNTGHPQVYGMFRDEFTNLRSQYGAGGFRFDFVRGYAP
ERVNSWMTDSADNSFCVGGLWKGPSEYPNWDWRNTASWQQIIKDWSDRAK
CPVFDFALKERMQNGSIADWKHGLNGNPDPRWREVAVTFVDNHDTGYSPG
QNGGQHHWALQDGLIRQAYAYILTSPGTPVVYWDHMYDWGYGDFIRQLIQ
VRRAAGVRADSAISFHSGYSGLVATVSGSQQTLVVALNSDLGNPGQVASG
SFSEAVNASNGQVRVWRS

3D structure

• PDB: 1qi4 Roles of catalytic residues in alpha-amylases as evidenced by the structures of the product-complexed mutants of a maltotetraose-forming amylase.
• Chain: A
• Resolution: 2.0 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): D193 G219 D294
• Catalytic site (residue number reindexed from 1): D193 G219 D294
• Enzyme Commision number: 3.2.1.60: glucan 1,4-alpha-maltotetraohydrolase.

Interaction with ligand

Site #	Ligand	Ligand chain	Binding residues on receptor (original residue number in PDB)	Binding residues on receptor (residue number reindexed from 1)	Binding affinity
BS01	GLC	A	H117 D193 H293 D294	H117 D193 H293 D294
BS02	GLC	A	W25 Q305	W25 Q305
BS03	GLC	A	W66 F79 I157	W66 F79 I157
BS04	GLC	A	F79 I157 G158 D160 A161	F79 I157 G158 D160 A161
BS05	CA	A	N116 D151 D154 D162 G197	N116 D151 D154 D162 G197
BS06	CA	A	D1 Q2 H13 D16 E17	D1 Q2 H13 D16 E17

Gene Ontology

Molecular Function

• GO:0004556 alpha-amylase activity
• GO:0043169 cation binding

Biological Process

• GO:0005975 carbohydrate metabolic process

External links

• PDB: RCSB:1qi4, PDBe:1qi4, PDBj:1qi4
• PDBsum: 1qi4
• PubMed: 10556241
• UniProt: P13507|AMT4_STUST Glucan 1,4-alpha-maltotetraohydrolase (Gene Name=amyP)