We report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyzes the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclization to form a cyclic monoterpene, CLPP. The structures of apo-CLDS and CLDS in complex with Tris, pyrophosphate, and Mg ion were refined at 2.00 Å resolution and 1.73 Å resolution, respectively. CLDS adopts a typical fold for cis-prenyl synthases and forms a homo-dimeric structure. An in vitro reaction using a regiospecifically H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction. The CLDS structure and structure-based mutagenesis provide mechanistic insights into this unprecedented terpene synthase. The combination of structural and mechanistic insights advances the knowledge of intricate terpene synthase-catalyzed reactions.

We report the three-dimensional structure of cyclolavandulyl diphosphate (CLPP) synthase (CLDS), which consecutively catalyzes the condensation of two molecules of dimethylallyl diphosphate (DMAPP) followed by cyclization to form ac yclic monoterpene,C LPP.T he structures of apo-CLDS and CLDS in complex with Tris,p yrophosphate,a nd Mg 2+ ion were refined at 2.00 resolution and 1.73 resolution, respectively.C LDS adopts at ypical fold for cisprenyl synthases and forms ah omo-dimeric structure.A n in vitro reaction using ar egiospecifically 2 H-substituted DMAPP substrate revealed the intramolecular proton transfer mechanism of the CLDS reaction. The CLDS structure and structure-based mutagenesis providem echanistic insights into this unprecedented terpene synthase.T he combination of structural and mechanistic insights advances the knowledge of intricate terpene synthase-catalyzed reactions.Terpenoids represent an important class of biologically active compounds owing to their structural diversity. [1,2] The diverse structures of terpenoids are derived from two simple 5-carbon units:i sopentenyl diphosphate (IPP) and DMAPP. An isoprenyl diphosphate synthase (IDS) catalyzes the canonical and sequential "head-to-tail" condensation of IPP to DMAPP to produce al onger acyclic polyprenyl diphosphate such as C 10 geranyl diphosphate (GPP) [eq. (1) in Scheme 1a]. Ther esulting acyclic polyprenyl diphosphate substrates can be cyclized by terpene cyclases into single-ring or multi-ring products,w hich can be further diversified by subsequent biosynthetic modifications. [3] Thus,i nt erpenoid biosynthesis,two independent enzymes,anIDS and acyclase, consecutively catalyze the condensation and cyclization reactions,r espectively,y ielding structurally diverse terpenoids.I ntriguingly,h owever, CLDS alone catalyzes the "head-to-middle" condensation of two molecules of Scheme 1. Terpene synthase reactions. a) eq. (1), condensation of IPP and DMAPP by GPP synthase;eq. (2), condensation of two molecules of DMAPP and subsequent cyclization by CLDS;e q. (3), condensation of two molecules of DMAPP by LPPS;e q. (4), condensation of DMAPP and GPP by Mcl22. b) Condensationo ftwo molecules of the deuterium-substituted DMAPP substrate (4)and subsequent cyclization catalyzed by CLDS. To simplify the figure, only key deuteriumatoms are shown in the intermediates, Int1, Int2 and Int3.

The stereoselective synthesis of the phomopsin A tripeptide side chain was achieved by using methyl 2-(((benzyloxy)carbonyl)amino)-2-(diphenoxyphosphoryl)acetate as a common synthetic precursor for the synthesis of E-Δ-dehydroisoleucine and E-Δ-aspartate.

Dedicated to Professor Yasuyuki Kita on cerebration on his 77th birthday Abstract -(2S,3R)-and (2S,3S)-2-amino-3-(3,4-dihydroxyphenyl)-3hydroxypropanoic acids (ADHP) are often found in an unusual amino acid component of phomopsin B, ustiloxins, RA-IV, and MPC1001B. Herein, we would like to report stereoselective synthesis of (2S,3R)-and (2S,3S)-ADHP equivalents for the synthesis of ADHP containing natural products. The synthesis is characterized by the stereocontrolled construction of the (2S,3R)-and (2S,3S)-stereocenters starting from Garner's aldehyde as a common starting material.