High Through-Put Genome Scanning For Novel Natural Products Exploration

Biosynthesis of natural products is a well-known process that employs small bioactive molecules as building blocks onto strutural complexity assembly with tandem reactions catalyzed by enzyme encoded secondary pathway specially.The cloning of biosynthetic genes of natural product can be easily achieved by obtaining a single gene related consisting in that genes involved in biosynthesis of natural products are usually clustered together with transcriptional regulator,resistant genes and other unknown genes on the genome of microorganisms.High-throughput genome scanning is a widely used method in probing the location of secondary metabolism genes specially for natural products biosynthesis of unknown structure owing to its independence on the structure in contrast to other strategies.In this dissertation,a novel gene scanning method has been developed in scaning on genomes of a hundred species actinomycetes by rationally designed primers of conserved regions of thiopeptide cyclase,non-ribosomal peptide synthetase(NRPS), typeâ… iterative polyketide synthetase(PKS) and N,N-dimethyltrasferase(in amino sugar biosynthesis,NDMT) respectively.6 NRPS,5 PKS,1 NDMT and 10 cyclase gene fragment has been cloned and sequenced by above means which can probably serve as entrance to unknown natural products.In GenBank database,the PCR product results have a high similarity to corresponding genes,and no identify sequence genes.So we can explain that they possible encode potential new-type functional gene.Using the newest result that cloning microorganism biosynthesis cluster, sequencing and functional analysis.And based on conserved motifs of synthetic gene in key point group,we design degenerate primer and screen scaling redundant actinomycete strain resources.We can got new-type antibiotic biosynthesis cluster.So based on new gene functional analysis and mature genetic manipulation system of different type antibiotic producing strain,we identify and dig new-type structural gene through combinatorial biosynthesis in order to produce many hybrid antibiotic, In the process of antibiotics biosynthetic pathway,similar structural feature unit may use similar enzymologist mechanism.On the level of protein and gene,the similar embodies conserved motifs in zymoprotein and structural gene.Though above-mentioned experimental result,we can design specificity cloning strategy aiming to aiming similar structural feature unit.It is an effective starting point to research specified antibiotics biosynthetic pathway.On the basis of sequence analysis,the genome scanning can find sufficient microorganism's potential from natural product.This will be a good method to finding new nature product.