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Terpenoid cyclases/Protein prenyltransferases superfamily
SCOP classification
Superfamily statistics
Functional annotation
| General category | Metabolism |
| Detailed category | Secondary metabolism |
Function annotation of SCOP domain superfamilies
InterPro annotation
| Cross references | IPR008930 SSF48239 Protein matches |
| Abstract | Protein prenyltransferases catalyze the transfer of the carbon moiety of C15 farnesyl pyrophosphate or geranylgeranyl pyrophosphate synthase to a conserved cysteine residue in a CaaX motif of protein and peptide substrates. The addition of a farnesyl group is required to anchor proteins to the cell membrane. In the 3D structure of a mammalian Ras farnesyltransferases (Ftase), both subunits are largely composed of alpha-helices. The alpha-2 to alpha-15 helices in the alpha subunit fold into a novel helical hairpin structure, resulting in a crescent-shape domain that envelopes part of the subunit. The 12 helices of the beta-subunit form an alpha-alpha barrel. Six additional helices connect the inner core of helices and form the outside of the helical barrel. A deep cleft surrounded by hydrophobic amino acids in the centre of the barrel is proposed as the FPP-binding pocket. A single Zn2+ ion is located at the junction between the hydrophilic surface groove near the subunit interface
Terpenoid cyclases such as squalene cyclase, pentalenene synthase,
5-epi-aristolochene synthase, and trichodiene synthase are responsible for the synthesis of cholesterol, a hydrocarbon precursor of the pentalenolactone family of antibiotics, a precursor of the antifungal phytoalexin capsidiol, and the precursor of antibiotics and mycotoxins, respectively. In the structures of these three enzymes, the similar structural feature referred to as 'terpenoid synthase fold' with 10-12 mostly antiparallel alpha-helices is found, as also observed in protein prenyltransferases. The high structural similarity provides support for the hypothesis that the three families of prenyltransferases have related evolution despite their low sequence similarity [ 12135472]. |
InterPro database
PDBeMotif information about ligands, sequence and structure motifs
PDBeMotif resource
Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation ]
Internal database links
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Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry
out SCOP domain assignments to all genomes at the superfamily level.
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Alignments of sequences to 12 models
in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical
are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.
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Browse and view proteins in genomes which have
different domain combinations including a Terpenoid cyclases/Protein prenyltransferases domain.
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Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.
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Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.
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There are 12 hidden Markov models representing the Terpenoid cyclases/Protein prenyltransferases superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.
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Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Internal database links ]
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