Part:BBa_K4621000

EctOperon is a cluster of genes encoding four enzymes that synthesize 5-Hydroxyectoine

Usage, Biology and Characterization： EctOperon contains ectA, ectB, ectC, and ectD. ectB is the coding sequence of L-2, 4-diaminobutyrate --2-oxoglutarate aminotransferase, L-Aspartate 4-semialdehyde can be converted to L-2,4-diaminobutanoate. ectA is the coding sequence for L-2,4-diaminobutyric acid acetyltransferase, L-2, 4-diaminobutanoate can be converted to N4-acetyl-L-2,4-diaminobutyrate. ectC is the coding sequence of L-ectoine synthase, which can convert N4-acetyl-L-2,4-diaminobutyrate to L-Ectoine. These three genes encode enzymes Ectoine: (4S)-2-methyl-1,4,5, 6-tetrahydropyrim idine-4-carboxylic acid, located on the same operon, forming the ectABC gene cluster. The Ectoine is then activated by ectoine hydroxylase, which is encoded by the ectD gene, to generate 5-Hydroxyectoine. "The synthesis of 5-Hydroxyectoine from L-Aspartate occurs naturally in some moderately halophilic microorganisms, as shown in Figure 1.

Streptomyces SCUT-3 was modified to overexpressed EctOperon. They were then seeded in a 40 mL LB medium system. After fermentation at 40 °C and 220 rpm for 72h, the product 5-Hydroxyectoine was determined as follows.