3UYK

Spinosyn Rhamnosyltransferase SpnG complexed with spinosyn aglycone

Summary for 3UYK

• Entry DOI: 10.2210/pdb3uyk/pdb
• Related: 3TSA 3UYL
• Descriptor: NDP-rhamnosyltransferase, MAGNESIUM ION, (2R,3aS,5aR,5bS,9S,13S,14R,16aS,16bR)-9-ethyl-2,13-dihydroxy-14-methyl-2,3,3a,5a,5b,6,9,10,11,12,13,14,16a,16b-tetradecahydro-1H-as-indaceno[3,2-d]oxacyclododecine-7,15-dione, ... (5 entities in total)
• Functional Keywords: glycosyltransferase, transferase
• Biological source: Saccharopolyspora spinosa
• Total number of polymer chains: 2
• Total formula weight: 82494.15

Authors

Isiorho, E.A.,Liu, H.-W.,Keatinge-Clay, A.T. (deposition date: 2011-12-06, release date: 2012-02-15, Last modification date: 2023-09-13)

Primary citation

Isiorho, E.A.,Liu, H.W.,Keatinge-Clay, A.T.
Structural Studies of the Spinosyn Rhamnosyltransferase, SpnG.
Biochemistry, 51:1213-1222, 2012

PubMed Abstract: Spinosyns A and D (spinosad), like many other complex polyketides, are tailored near the end of their biosyntheses through the addition of sugars. SpnG, which catalyzes their 9-OH rhamnosylation, is also capable of adding other monosaccharides to the spinosyn aglycone (AGL) from TDP-sugars; however, the substitution of UDP-D-glucose for TDP-D-glucose as the donor substrate is known to result in a >60000-fold reduction in k(cat). Here, we report the structure of SpnG at 1.65 Å resolution, SpnG bound to TDP at 1.86 Å resolution, and SpnG bound to AGL at 1.70 Å resolution. The SpnG-TDP complex reveals how SpnG employs N202 to discriminate between TDP- and UDP-sugars. A conformational change of several residues in the active site is promoted by the binding of TDP. The SpnG-AGL complex shows that the binding of AGL is mediated via hydrophobic interactions and that H13, the potential catalytic base, is within 3 Å of the nucleophilic 9-OH group of AGL. A model for the Michaelis complex was constructed to reveal the features that allow SpnG to transfer diverse sugars; it also revealed that the rhamnosyl moiety is in a skew-boat conformation during the transfer reaction.

PubMed: 22283226
DOI: 10.1021/bi201860q

Experimental method

X-RAY DIFFRACTION (1.7 Å)