Structure of PDB 1aqi Chain A

Receptor sequence

>1aqiA (length=382) Species: 271 (Thermus aquaticus)

VETPPEVVDFMVSLAEAPRGGRVLEPACAHGPFLRAFREAHGTGYRFVGV
EIDPKALDLPPWAEGILADFLLWEPGEAFDLILGNPPYGIVKAVKDLYKK
AFSTWKGKYNLYGAFLEKAVRLLKPGGVLVFVVPATWLVLEDFALLREFL
AREGKTSVYYLGEVFPQKKVSAVVIRFQKSGKGLSLWDTQESESGFTPIL
WAEYPHWEGEIIRFETEETRKLEISGMPLGDLFHIRFAARSPEFKKHPAV
RKEPGPGLVPVLTGRNLKPGWVDYEKNHSGLWMPKERAKELRDFYATPHL
VVAHTKGTRVVAAWDERAYPWREEFHLLPKEGVRLDPSTLVQWLNSEAMQ
KHVRTLYRDFVPHLTLRMLERLPVRREYGFHT

3D structure

• PDB: 1aqi Differential binding of S-adenosylmethionine S-adenosylhomocysteine and Sinefungin to the adenine-specific DNA methyltransferase M.TaqI.
• Chain: A
• Resolution: 2.6 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): N105 P106 Y108 F196
• Catalytic site (residue number reindexed from 1): N85 P86 Y88 F165
• Enzyme Commision number: 2.1.1.72: site-specific DNA-methyltransferase (adenine-specific).

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	SAH	A	V21 A47 E71 I72 D89 F90 N105 P107 Y108	V1 A27 E51 I52 D69 F70 N85 P87 Y88	PDBbind-CN: -logKd/Ki=5.62,Kd=2.4uM

Gene Ontology

Molecular Function

• GO:0003676 nucleic acid binding
• GO:0003677 DNA binding
• GO:0008168 methyltransferase activity
• GO:0009007 site-specific DNA-methyltransferase (adenine-specific) activity

Biological Process

• GO:0006304 DNA modification
• GO:0009307 DNA restriction-modification system
• GO:0032259 methylation

External links

• PDB: RCSB:1aqi, PDBe:1aqi, PDBj:1aqi
• PDBsum: 1aqi
• PubMed: 8995524
• UniProt: P14385|MTTA_THEAQ Type II methyltransferase M.TaqI (Gene Name=taqIM)