Structure of PDB 3i5u Chain B

Receptor sequence

>3i5uB (length=325) Species: 167636 (Streptomyces carzinostaticus subsp. neocarzinostaticus)

AAHIGLRALADLATPMAVRVAATLRVADHIAAGHRTAAEIASAAGAHADS
LDRLLRHLVAVGLFTRDGQGVYGLTEFGEQLRDDHAAGKRKWLDMNSAVG
RGDLGFVELAHSIRTGQPAYPVRYGTSFWEDLGSDPVLSASFDTLMSHHL
ELDYTGIAAKYDWAALGHVVDVGGGSGGLLSALLTAHEDLSGTVLDLQGP
ASAAHRRFLDTGLSGRAQVVVGSFFDPLPAGAGGYVLSAVLHDWDDLSAV
AILRRCAEAAGSGGVVLVIEAVAGAGTGMDLRMLTYFGGKERSLAELGEL
AAQAGLAVRAAHPISYVSIVEMTAL

3D structure

• PDB: 3i5u Molecular basis of substrate promiscuity for the SAM-dependent O-methyltransferase NcsB1, involved in the biosynthesis of the enediyne antitumor antibiotic neocarzinostatin.
• Chain: B
• Resolution: 2.6 Å

Enzymatic activity

• Catalytic site (original residue number in PDB): H246 D247 E274 E298
• Catalytic site (residue number reindexed from 1): H242 D243 E270 E291
• Enzyme Commision number: 2.1.1.303: 2,7-dihydroxy-5-methyl-1-naphthoate 7-O-methyltransferase.

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	SAM	B	W133 M150 H153 G177 D200 L201 S227 F228 S242 D247	W129 M146 H149 G173 D196 L197 S223 F224 S238 D243
BS02	5NA	B	W96 F146 M150 M286 R289 Y293	W92 F142 M146 M279 R282 Y286

Gene Ontology

Molecular Function

• GO:0008168 methyltransferase activity
• GO:0008171 O-methyltransferase activity

Biological Process

• GO:0017000 antibiotic biosynthetic process
• GO:0032259 methylation

External links

• PDB: RCSB:3i5u, PDBe:3i5u, PDBj:3i5u
• PDBsum: 3i5u
• PubMed: 19702337
• UniProt: Q84HC8|NCSB1_STRCZ 2,7-dihydroxy-5-methyl-1-naphthoate 7-O-methyltransferase (Gene Name=ncsB1)