Abstract
Microsomal elongases are proteins catalyzing the condensation of malonyl-CoA with acyl-CoA chains, the first and rate-limiting step in microsomal fatty acid elongation. Here we report the measurement of elongase activity of a microsomal enriched fraction from the marine microalga Pavlova lutheri (P. lutheri). By directly monitoring the production of C2 elongated acyl-CoA from a range of saturated and monounsaturated acyl-CoA substrates, we found that saturated 16:0-CoA is the preferred substrate for this elongase complex. Analysis of an EST database prepared from the exponential stage of growth of P. lutheri revealed the most abundant identifiable enzyme as a cDNA, Plelo1, encoding a protein similar to the plant beta-ketoacyl-coenzyme A synthases (KCS, also known as elongases). Plelo1 is a single copy gene in the algal genome and gene expression analysis showed it to be highly expressed during the exponential phase of growth. It is suggested that microsomal elongation of 16:0-CoA represents a key intermediate step in the biosynthesis of the health beneficial very long chain polyunsaturated fatty acids eicosapentaenoic (20:5n3) and docosahexaenoic (22:6n3) acids.
| Original language | English |
|---|---|
| Pages (from-to) | 111-118 |
| Number of pages | 8 |
| Journal | Journal of applied phycology |
| Volume | 17 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Mar 2005 |
Keywords
- acyl-CoA
- cDNA library
- elongase
- elongation activity
- Pavlova lutheri
- FATTY-ACID ELONGATION
- DOCOSAHEXAENOIC ACID
- TRANSGENIC PLANTS
- FAE1 KCS
- SYNTHASE
- IDENTIFICATION
- BIOSYNTHESIS
- ENZYMES