TY - JOUR
T1 - X-ray analysis of butirosin biosynthetic enzyme BtrN redefines structural motifs for AdoMet radical chemistry
AU - Goldman, Peter J.
AU - Groèe, Tyler L.
AU - Booker, Squire J.
AU - Drennan, Catherine L.
PY - 2013/10/1
Y1 - 2013/10/1
N2 - The 2-deoxy-scyllo-inosamine (DOIA) dehydrogenases are key enzymes in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics. In contrast to most DOIA dehydrogenases, which are NAD-dependent, the DOIA dehydrogenase from Bacillus circulans (BtrN) is an S-adenosyl-L-methionine (AdoMet) radical enzyme. To examine how BtrN employs AdoMet radical chemistry, we haèe determined its structure with AdoMet and substrate to 1.56 A resolution. We find a preèiously undescribed modification to the core AdoMet radical fold: instead of the canonical (β/α)6 architecture, BtrN displays a (β5/α4) motif. We further find that an auxiliary [4Fe-4S] cluster in BtrN, thought to bind substrate, is instead implicated in substrate-radical oxidation. High structural homology in the auxiliary cluster binding region between BtrN, fellow AdoMet radical dehydrogenase anSME, and molybdenum cofactor biosynthetic enzyme MoaA proèides support for the establishment of an AdoMet radical structural motif that is likely common to 6,400 uncharacterized AdoMet radical enzymes.
AB - The 2-deoxy-scyllo-inosamine (DOIA) dehydrogenases are key enzymes in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics. In contrast to most DOIA dehydrogenases, which are NAD-dependent, the DOIA dehydrogenase from Bacillus circulans (BtrN) is an S-adenosyl-L-methionine (AdoMet) radical enzyme. To examine how BtrN employs AdoMet radical chemistry, we haèe determined its structure with AdoMet and substrate to 1.56 A resolution. We find a preèiously undescribed modification to the core AdoMet radical fold: instead of the canonical (β/α)6 architecture, BtrN displays a (β5/α4) motif. We further find that an auxiliary [4Fe-4S] cluster in BtrN, thought to bind substrate, is instead implicated in substrate-radical oxidation. High structural homology in the auxiliary cluster binding region between BtrN, fellow AdoMet radical dehydrogenase anSME, and molybdenum cofactor biosynthetic enzyme MoaA proèides support for the establishment of an AdoMet radical structural motif that is likely common to 6,400 uncharacterized AdoMet radical enzymes.
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U2 - 10.1073/pnas.1312228110
DO - 10.1073/pnas.1312228110
M3 - Article
C2 - 24048029
AN - SCOPUS:84885045053
SN - 0027-8424
VL - 110
SP - 15949
EP - 15954
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 40
ER -