Promoter and recombinant expression vector as well as application thereof and method for expressing heterologous proteins

Abstract

The invention discloses a promoter. The length of the promoter is 150-1000bp, wherein the promoter comprises a nucleic acid fragment expressed as SEQ ID NO.1; the promoter is capable of starting the transcription in bacillus subtilis. The invention also provides a recombinant expression vector; a reading frame is allowed to be inserted into the recombinant expression vector and is used for expressing protein in bacteria; a promoter of the recombinant expression vector comprises the promoter. The invention further provides a method for expressing heterologous proteins. The method comprises a step of inserting the reading frame for encoding the heterologous proteins into the recombinant expression vector to prepare recombinant expression plasmids. The invention also provides application of the promoter to preparation of the recombinant expression vector and / or expressing the proteins in the plasmids. By virtue of the technical scheme, the expression quantity of the heterologous proteins can be obviously increased without induction.

Description

Technical field

[0001] The present invention relates to the field of biotechnology, in particular to a promoter, a recombinant expression vector, a method for expressing foreign proteins and the use of the promoter. Background technique

[0002] A promoter is a DNA sequence located in the upstream region of the 5'end of a structural gene, which can activate RNA polymerase to accurately bind to the template DNA and have the specificity of transcription initiation. Because the specific transcription of a gene depends on whether the enzyme and the promoter can effectively form a binary complex, how the RNA polymerase effectively finds the promoter and combines with it is the first problem to be solved in the transcription initiation process. Experiments have shown that for many promoters, the rate at which RNA polymerase binds to it is at least 100 times higher than random collisions in Brownian motion.

[0003] The transcriptional activity of different promoters is quite different. ...

Examples

Embodiment 1

[0031] This example is used to illustrate the method for obtaining the promoter of the present invention.

[0032] The DNA was prepared by using Tiangen bacterial genome extraction reagent, operating according to its instructions, and using Bacillus subtilis WB600 strain. Using the primers shown in Table 1, the prepared DNA was amplified, and the amplified products were DNA sequenced. The results showed that the amplified products were of different lengths with restriction endonuclease sites and protective groups. The promoter shown in SEQ IE NO.1-5.

[0033] Table 1

[0034]

Technical field

[0001] The present invention relates to the field of biotechnology, in particular to a promoter, a recombinant expression vector, a method for expressing foreign proteins and the use of the promoter. Background technique

[0002] A promoter is a DNA sequence located in the upstream region of the 5'end of a structural gene, which can activate RNA polymerase to accurately bind to the template DNA and have the specificity of transcription initiation. Because the specific transcription of a gene depends on whether the enzyme and the promoter can effectively form a binary complex, how the RNA polymerase effectively finds the promoter and combines with it is the first problem to be solved in the transcription initiation process. Experiments have shown that for many promoters, the rate at which RNA polymerase binds to it is at least 100 times higher than random collisions in Brownian motion.

[0003] The transcriptional activity of different promoters is quite different. ...

Examples

Embodiment 1

[0031] This example is used to illustrate the method for obtaining the promoter of the present invention.

[0032] The DNA was prepared by using Tiangen bacterial genome extraction reagent, operating according to its instructions, and using Bacillus subtilis WB600 strain. Using the primers shown in Table 1, the prepared DNA was amplified, and the amplified products were DNA sequenced. The results showed that the amplified products were of different lengths with restriction endonuclease sites and protective groups. The promoter shown in SEQ IE NO.1-5.

[0033] Table 1

[0034]

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