Literature summary for 1.3.3.16 extracted from

Ghilarov, D.; Stevenson, C.EM.; Travin, D.Y.; Piskunova, J.; Serebryakova, M.; Maxwell, A.; Lawson, D.M.; Severinov, K.
Architecture of microcin B17 synthetase an octameric protein complex converting a ribosomally synthesized peptide into a DNA gyrase poison (2019), Mol. Cell, 73, 749-762 .

Crystallization (Commentary)

Crystallization (Comment)	Organism
structures of synthetase McbBCD reveal an octameric B4C2D2 complex with two bound substrate peptides. Each McbB dimer clamps the N-terminal recognition sequence, while the C-terminal heterocycle of the modified peptide is trapped in the active site of McbC. The McbD and McbC active sites are distant from each other, which necessitates alternate shuttling of the peptide substrate between them, while remaining tethered to the McbB dimer	Escherichia coli

Crystallization (Comment)

Organism

structures of synthetase McbBCD reveal an octameric B4C2D2 complex with two bound substrate peptides. Each McbB dimer clamps the N-terminal recognition sequence, while the C-terminal heterocycle of the modified peptide is trapped in the active site of McbC. The McbD and McbC active sites are distant from each other, which necessitates alternate shuttling of the peptide substrate between them, while remaining tethered to the McbB dimer

Escherichia coli

Organism

Organism	UniProt	Comment	Textmining
Escherichia coli	P23185	dehydrogenase subunit McbC	-

Purification (Commentary)

Purification (Comment)	Organism
copurification of the modified McbA peptide together with all three components of the microcin B17 synthetase as a stable complex	Escherichia coli

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
a [protein]-(1S,4R)-2-(C-substituted-aminomethyl)-4-acyl-2-thiazoline + O2	-	Escherichia coli	a [protein]-(S)-2-(C-substituted-aminomethyl)-4-acyl-1,3-thiazole + H2O2	-	?
a [protein]-(S,S)-2-(C-substituted-aminomethyl)-4-acyl-2-oxazoline + O2	-	Escherichia coli	a [protein]-(S)-2-(C-substituted-aminomethyl)-4-acyl-1,3-oxazole + H2O2	-	?
a [protein]-(S,S)-2-(C-substituted-aminomethyl)-4-acyl-5-methyl-2-oxazoline + O2	-	Escherichia coli	a [protein]-(S)-2-(C-substituted-aminomethyl)-4-acyl-5-methyl-1,3-oxazole + H2O2	-	?
additional information	proposed general mechanism for McbC: an activated Tyr202 abstracts a proton from the A carbon of an azoline substrate, which results in E2 elimination of the antiproton from the B carbon and hydride transfer to FMN. Instead of a proton being provided to FMN by a general base to yield FMNH2, the negative charge on N1 of FMN may be stabilized by a salt bridge with Arg233	Escherichia coli	?	-	-

Synonyms

Synonyms	Comment	Organism
MbcC	-	Escherichia coli
microcin B17-processing protein McbC	-	Escherichia coli

Cofactor

Cofactor	Comment	Organism	Structure
FMN	each McbC subunit contributes to the binding of the FMN cofactor molecules, with Arg82 of one McbC subunit and Arg117 of the other forming salt bridges with the phosphate group and Arg181 interacting with the O2 of FMN	Escherichia coli

General Information

General Information	Comment	Organism
physiological function	during biosynthesis of microcin B17, azole introduction into the microcin B17 precursor requires coordination of the activities of the heterocyclase, which converts Ser and Cys residues into azolines, and the dehydrogenase, which oxidizes the azolines to azoles	Escherichia coli