期刊
ACS CHEMICAL BIOLOGY
卷 7, 期 12, 页码 1994-2003出版社
AMER CHEMICAL SOC
DOI: 10.1021/cb300385m
关键词
-
资金
- NIH [R01 DK42303, R01 CA108874, U01 TW007404]
- Hans W. Vahlteich Professorship
- NIH National Institute of General Medical Sciences (GM) [Y1-GM-1104]
- National Cancer Institute (CA) through the GM/CA at the APS [Y1-CO-1020]
- U.S. Department of Energy
Sulfated molecules with diverse functions are common in biology, but sulfonation as a method to activate a metabolite for chemical catalysis is rare. Catalytic activity was characterized and crystal structures were determined for two such activating sulfotransferases (STs) that sulfonate beta-hydroxyacyl thioester substrates. The CurM polyketide synthase (PKS) ST domain from the curacin A biosynthetic pathway of Moorea producens and the olefin synthase (OLS) ST from a hydrocarbon-producing system of Synechococcus PCC 7002 both occur as a unique acyl carrier protein (ACP), ST, and thioesterase (TE) tridomain within a larger polypeptide. During pathway termination, these cyanobacterial systems introduce a terminal double bond into the beta-hydroxyacyl-ACP-linked substrate by the combined action of the ST and TE. Under in vitro conditions, CurM PKS ST and OLS ST acted on beta-hydroxy fatty acyl-ACP substrates; however, OLS ST was not reactive toward analogues of the natural PKS ST substrate bearing a CS-methoxy substituent. The crystal structures of CurM ST and OLS ST revealed that they are members of a distinct protein family relative to other prokaryotic and eukaryotic sulfotransferases. A common binding site for the sulfonate donor 3'-phosphoadenosine-5'-phosphosulfate was visualized in complexes with the product 3'-phosphoadenosine-5'-phosphate. Critical functions for several conserved amino acids in the active site were confirmed by site-directed mutagenesis, including a proposed glutamate catalytic base. A dynamic active-site flap unique to the activating ST family affects substrate selectivity and product formation, based on the activities of chimeras of the PKS and OLS STs with exchanged active-site flaps.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据