4GOX

Sulfotransferase Domain from the Synechococcus PCC 7002 Olefin Synthase

Summary for 4GOX

• Entry DOI: 10.2210/pdb4gox/pdb
• Descriptor: Polyketide synthase, ADENOSINE-3'-5'-DIPHOSPHATE (3 entities in total)
• Functional Keywords: olefin synthase, polyketide synthase, hydrocarbon, sulfotransferase, paps, pap, 3'phosphoadenosine-5'phosphosulfate, transferase
• Biological source: Synechococcus sp.
• Total number of polymer chains: 1
• Total formula weight: 35862.21

Authors

McCarthy, J.G.,Smith, J.L. (deposition date: 2012-08-20, release date: 2012-10-17, Last modification date: 2024-02-28)

Primary citation

McCarthy, J.G.,Eisman, E.B.,Kulkarni, S.,Gerwick, L.,Gerwick, W.H.,Wipf, P.,Sherman, D.H.,Smith, J.L.
Structural basis of functional group activation by sulfotransferases in complex metabolic pathways.
Acs Chem.Biol., 7:1994-2003, 2012

PubMed Abstract: 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 β-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 β-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 β-hydroxy fatty acyl-ACP substrates; however, OLS ST was not reactive toward analogues of the natural PKS ST substrate bearing a C5-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.

PubMed: 22991895
DOI: 10.1021/cb300385m

Experimental method

X-RAY DIFFRACTION (2.15 Å)