Structure of PDB 1tw8 Chain B

Receptor sequence

>1tw8B (length=256) Species: 727 (Haemophilus influenzae)

SFIKPIYQDINSILIGQKVKRPKSGTLSGHAAGEPFEKLVYKFLKENLSD
LTFKQYEYLNDLFMKNPAIIGHEARYKLFNSPTLLFLLSRGKAATENWSI
ENLFEEKQNDTADILLVKDQFYELLDVKTRNISKSAQAPNIISAYKLAQT
CAKMIDNKEFDLFDINYLEVDWELNGEDLVCVSTSFAELFKSEPSELYIN
WAAAMQIQFHVRDLDQGFNGTREEWAKSYLKHFVTQAEQRAISMIDKFVK
PFKKYI

3D structure

• PDB: 1tw8 Ca2+ binding in the active site of HincII: implications for the catalytic mechanism
• Chain: B
• Resolution: 2.8 Å

Enzymatic activity

• Enzyme Commision number: 3.1.21.4: type II site-specific deoxyribonuclease.

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	dna	B	G30 H31 Q109 N110 D114 D127 T130 R131 S136 A137 Q138 A139 P140 N141 S144 Y146 K147 Q207	G29 H30 Q108 N109 D113 D126 T129 R130 S135 A136 Q137 A138 P139 N140 S143 Y145 K146 Q206	PDBbind-CN: Kd=1.14nM
BS02	dna	B	Y77 S90 K93 K108 Q109 Q138 Y199 N201 A203 A204 R241 K248	Y76 S89 K92 K107 Q108 Q137 Y198 N200 A202 A203 R240 K247	PDBbind-CN: Kd=1.14nM
BS03	CA	B	D114 D127 V128	D113 D126 V127
BS04	NA	B	D127 I142 I143	D126 I141 I142

Gene Ontology

Molecular Function

• GO:0003677 DNA binding
• GO:0004519 endonuclease activity
• GO:0009036 type II site-specific deoxyribonuclease activity

Biological Process

• GO:0009307 DNA restriction-modification system

External links

• PDB: RCSB:1tw8, PDBe:1tw8, PDBj:1tw8
• PDBsum: 1tw8
• PubMed: 15491133
• UniProt: P17743|T2C2_HAEIF Type II restriction enzyme HincII (Gene Name=hincIIR)