This plastidial enzyme is able to insert a cis double bond in monounsaturated fatty acids incorporated into glycerolipids. The enzyme introduces the new bond at a position 3 carbons away from the existing double bond, towards the methyl end of the fatty acid. The native substrates are oleoyl (18:1 Delta9) and (Z)-hexadec-7-enoyl (16:1 Delta7) groups attached to either position of the glycerol backbone in glycerolipids, resulting in the introduction of the second double bond at positions 12 and 10, respectively This prompted the suggestion that this is an omega6 desaturase. However, when acting on palmitoleoyl groups(16:1 Delta9), the enzyme introduces the second double bond at position 12 (omega4), indicating it is an (n+3) desaturase . cf. EC 1.14.19.34, acyl-lipid (9+3)-(E)-desaturase.
This plastidial enzyme is able to insert a cis double bond in monounsaturated fatty acids incorporated into glycerolipids. The enzyme introduces the new bond at a position 3 carbons away from the existing double bond, towards the methyl end of the fatty acid. The native substrates are oleoyl (18:1 Delta9) and (Z)-hexadec-7-enoyl (16:1 Delta7) groups attached to either position of the glycerol backbone in glycerolipids, resulting in the introduction of the second double bond at positions 12 and 10, respectively This prompted the suggestion that this is an omega6 desaturase. However, when acting on palmitoleoyl groups(16:1 Delta9), the enzyme introduces the second double bond at position 12 (omega4), indicating it is an (n+3) desaturase [3]. cf. EC 1.14.19.34, acyl-lipid (9+3)-(E)-desaturase.
the main product arising from desaturation of 16:1(9c) appears to be the 16:2(9,12) isomer and is thus an omega-4 desaturation product rather than an omega-6 desaturation product
the production of the omega-4 product when 16:1(9c) is the available substrate suggests that the enzyme introduces the second double bond in a methylene-interrupted configuration measuring from the first double bond rather than from the methyl end of the fatty acid
the enzyme measures the insertion of the new double bond from the methyl end and the existing (n-9)-cis double bond of an appropriate acyl or alkyl chain. The distal part of the substrate group, normally the carboxy end of a fatty acyl residue, is of less importance and, in particular, its activation in thioester form is not required
the enzyme measures the insertion of the new double bond from the methyl end and the existing (n-9)-cis double bond of an appropriate acyl or alkyl chain. The distal part of the substrate group, normally the carboxy end of a fatty acyl residue, is of less importance and, in particular, its activation in thioester form is not required
compared with the wild type plants, the fad6 mutant shows reduced tolerance to salt stress, and accumulates more Na+ and less K+ under high NaCl stress condition. Furthermore, cellular oxidative damage is more severe in the fad6 mutant when treated with high concentrations of NaCl
complementation of the fad6 mutant line of Arabidopsis. The fatty acid composition of the rosette leaves of these plants shows a partially or fully restored accumulation of 16:3 fatty acids, indicating complementation of the primary biochemical deficiency
stress signals including salt and mannitol significantly induce the expression of the enzyme. Upon treatment with 300 mM NaCl or 300 mM mannitol, the transcriptional level of the enzyme increases after 24 h