TY - JOUR
T1 - The product chain length determination mechanism of type II geranylgeranyl diphosphate synthase requires subunit interaction
AU - Noike, Motoyoshi
AU - Katagiri, Takashi
AU - Nakayama, Toru
AU - Koyama, Tanetoshi
AU - Nishino, Tokuzo
AU - Hemmi, Hisashi
PY - 2008/8
Y1 - 2008/8
N2 - The product chain length determination mechanism of type II geranylgeranyl diphosphate synthase from the bacterium, Pantoea ananatis, was studied. In most types of short-chain (all-E) prenyl diphosphate synthases, bulky amino acids at the fourth and/or fifth positions upstream from the first aspartate-rich motif play a primary role in the product determination mechanism. However, type II geranylgeranyl diphosphate synthase lacks such bulky amino acids at these positions. The second position upstream from the G(Q/E) motif has recently been shown to participate in the mechaism of chain length determination in type III geranylgeranyl diphosphate synthase. Amino acid substitutions adjacent to the residues upstream from the first aspartate-rich motif and from the G(Q/E) motif did not affect the chain length of the final product. Two amino acid insertion in the first aspartate-rich motif, which is typically found in bacterial enzymes, is thought to be involved in the product determination mechanism. However, deletion mutation of the insertion had no effect on product chain length. Thus, based on the structures of homologous enzymes, a new line of mutants was constructed in which bulky amino acids in the α-helix located at the expected subunit interface were replaced with alanine. Two mutants gave products with longer chain lengths, suggesting that type II geranylgeranyl diphosphate synthase utilizes an unexpected mechanism of chain length determination, which requires subunit interaction in the homooligomeric enzyme. This possibility is strongly supported by the recently determined crystal structure of plant type II geranylgeranyl diphosphate synthase.
AB - The product chain length determination mechanism of type II geranylgeranyl diphosphate synthase from the bacterium, Pantoea ananatis, was studied. In most types of short-chain (all-E) prenyl diphosphate synthases, bulky amino acids at the fourth and/or fifth positions upstream from the first aspartate-rich motif play a primary role in the product determination mechanism. However, type II geranylgeranyl diphosphate synthase lacks such bulky amino acids at these positions. The second position upstream from the G(Q/E) motif has recently been shown to participate in the mechaism of chain length determination in type III geranylgeranyl diphosphate synthase. Amino acid substitutions adjacent to the residues upstream from the first aspartate-rich motif and from the G(Q/E) motif did not affect the chain length of the final product. Two amino acid insertion in the first aspartate-rich motif, which is typically found in bacterial enzymes, is thought to be involved in the product determination mechanism. However, deletion mutation of the insertion had no effect on product chain length. Thus, based on the structures of homologous enzymes, a new line of mutants was constructed in which bulky amino acids in the α-helix located at the expected subunit interface were replaced with alanine. Two mutants gave products with longer chain lengths, suggesting that type II geranylgeranyl diphosphate synthase utilizes an unexpected mechanism of chain length determination, which requires subunit interaction in the homooligomeric enzyme. This possibility is strongly supported by the recently determined crystal structure of plant type II geranylgeranyl diphosphate synthase.
KW - Farnesyl diphosphate synthase
KW - Geranylgeranyl diphosphate synthase
KW - Isoprenoid
KW - Mutagenesis
KW - Prenyltransferase
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U2 - 10.1111/j.1742-4658.2008.06538.x
DO - 10.1111/j.1742-4658.2008.06538.x
M3 - Article
C2 - 18616462
AN - SCOPUS:47249088353
VL - 275
SP - 3921
EP - 3933
JO - FEBS Journal
JF - FEBS Journal
SN - 1742-464X
IS - 15
ER -