OBJECTIVETo screen enhancer-like sequences from Escherichia coli strain C600 genome, to construct an expression vector harboring prokaryotic enhancer-like sequence and study the effect of interferon gene expression.

METHODSEnhancer-like element from Escherichia coli strain C600 genome was obtained by using the chloramphenicol acetyl-transferase (CAT) gene as reporter gene. An expression vector harboring prokaryotic enhancer-like sequence from Escherichia coli strain C600 was constructed. Interferon was expressed and assayed.

RESULTSAn enhancer-like sequences with distance and orientation independence property were screened and named 3A. Quantification test showed that the direct and reverse orientation of 3A could increase the activity of beta-galactosidase with 7.11 and 2.93 times. The enhancing activity of the element was on transcription level. An expression vector harboring the prokaryotic enhancer-like sequence 3P3 which was enhancing function region of sequence 3A was constructed. Using this vector the antiviral activity of interferon alpha-2b was increased by 3.7 times in comparison with the original expression plasmid.

CONCLUSION3A enhancer-like sequence was screened from Escherichia coli strain C600 genome. Interferon gene was highly expressed by using an expression vector harboring enhancer-like sequences.