To prokaryotic express prokaryotically and to purify the efaA protein from Enterococus faecalis so as to provide the basis for the further study on the pathogenesis and clinical sero-diagnosis of endocarditis caused by E.faecalis, efaA gene of E.faecalis was amplified by PCR, the PCR-amplified product was digested with restriction enzymes and cloned into prokaryotic vector pET32a to construct the recombinant plasmid pET30a/efaA. This recombinant plasmid was confirmed by double enzyme digestion with BamhI and Xhol and then subjected to sequencing, and transformed to E.coli BL21 (DE3). Expression of the fusion protein was induced by IPTG, and analyzed by SDS-PAGE and Western blotting. The recombinant fusion protein was purified by His-binding affinity chromatography.It was shown that efaA gene of 943 bp in size was amplified from Enterococus faecalis and the recombinant plasmid pET30a,/ efaA was successfully constructed and expressed in E.coli BL21. The purified product was found to be 34 kDa in molecular weight as demonstrated by SDS-PAGE and Western blotting. It is evident that the efaA protein of E.faecalis can be successfully expressed and purified.

Objective To identify and analyze the bioinformatics and expression patterns of the F-box-LRR(FBXL)gene family of Salvia miltiorrhiza based on genomic data,and provide a foundation for further elucidating its gene functions.Methods The SmFBXL gene was identified from the Salvia miltiorrhiza genomic database.Its gene structure features,promoter cis-acting elements,physicochemical properties of encoded proteins,evolutionary relationships,and tissue expression were analyzed by bioinformatics methods and online tools.Results A total of 104 SmFBXL genes were identified from the Salvia miltiorrhiza genome,unevenly distributed on 8 chromosomes,with upstream promoters containing cis-acting elements related to plant stress resistance,growth and development,and hormone response.A phylogenetic tree of the FBXL family members of Salvia miltiorrhiza,Arabidopsis thaliana,and Glycine max was constructed,dividing the 104 SmFBXL genes into 7 subfamilies.Through homologous evolution analysis,it was speculated that SmFBXL36 might be involved in defense against pathogen invasion,SmFBXL86 and SmFBXL79 might play important roles in regulating lateral root growth in Salvia miltiorrhiza,and SmFBXL11 and SmFBXL40 might regulate hypocotyl growth.Transcriptome data showed differential expression of SmFBXL genes in different tissues of Salvia miltiorrhiza,with 13 SmFBXL genes showing higher expression levels in roots and leaves,serving as candidate genes for further research on the SmFBXL gene family.Conclusion The research results provided a reference for further elucidating the regulatory mechanisms of SmFBXL genes in stress response and secondary metabolite biosynthesis in Salvia miltiorrhiza.