2azk
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Crystal structure for the mutant W136E of Sulfolobus solfataricus hexaprenyl pyrophosphate synthase
OverviewOverview
Hexaprenyl pyrophosphate synthase (HexPPs) from Sulfolobus solfataricus, catalyzes the synthesis of trans-C(30)-hexaprenyl pyrophosphate (HexPP) by, reacting two isopentenyl pyrophosphate molecules with one geranylgeranyl, pyrophosphate. The crystal structure of the homodimeric C(30)-HexPPs, resembles those of other trans-prenyltransferases, including farnesyl, pyrophosphate synthase (FPPs) and octaprenyl pyrophosphate synthase, (OPPs). In both subunits, 10 core helices are arranged about a central, active site cavity. Leu164 in the middle of the cavity controls the, product chain length. Two protein conformers are observed in the S., solfataricus HexPPs structure, and the major difference between them, occurs in the flexible region of residues 84 to 100. Several helices, (alphaI, alphaJ, alphaK, and part of alphaH) and the associated loops have, high-temperature factors in one monomer, which may be related to the, domain motion that controls the entrance to the active site. Different, side chain conformations of Trp136 in two HexPPs subunits result in weaker, hydrophobic interactions at the dimer interface, in contrast to the, symmetric pi-pi stacking interactions of aromatic side chains found in, FPPs and OPPs. Finally, the three-conformer switched model may explain the, catalytic process for HexPPs.
About this StructureAbout this Structure
2AZK is a Single protein structure of sequence from Sulfolobus solfataricus. Active as Dimethylallyltranstransferase, with EC number 2.5.1.1 Full crystallographic information is available from OCA.
ReferenceReference
Homodimeric hexaprenyl pyrophosphate synthase from the thermoacidophilic crenarchaeon Sulfolobus solfataricus displays asymmetric subunit structures., Sun HY, Ko TP, Kuo CJ, Guo RT, Chou CC, Liang PH, Wang AH, J Bacteriol. 2005 Dec;187(23):8137-48. PMID:16291686
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