The gene encoding an esterase enzyme was cloned from a metagenomic library of cow rumen bacteria. The esterase gene (est2R) was 2,120 bp in length, encoding a protein of 516 amino acid residues with a calculated molecular weight of 57,286 Da. The molecular weight of the enzyme was estimated to be 57,000 Da by SDS-PAGE. Est2R shared 35.6% amino acid identity with esterase (CAH19079) of uncultured prokaryote. The Est2R was most active at 20-40°C, and showed optimum at 30°C and pH 8.0. The most activity of Est2R for the different chain length of p-nitrophenyl ester group as substrate was p-nitrophenyl acetate. Moreover, the enzyme was found to be most active without organic solvent, followed by 98% active with ethanol, and the enzyme activity was highly affected by the acetonitrile. The enzyme was significantly inhibited by Zn2+ but stimulated by Ca2+. So, novel esterase gene est2R is likely to obtain from cow rumen metagenome and supposed to use for industrial purpose.

머루(Vitis coignetiae)는 국내에 자생하는 야생종 포도의 한 종류로서, 포도 새눈무늬병에 저항성이다. 내병성 포도 육종에 활용할 유용한 육종소재를 개발하고자 머루의 잎과 과실로부터 cDNA libraray를 제작하였다. 머루의 cDNA library의 총 5,760개의 EST 클론을 분석하여 676개의 contig와 2,306개의 singleton을 분리하여 총 2,982개의 unigene을 분리하였다. NCBI 데이터베이스의 BLAST를 통한 상동성을 검색한 결과, 2,241개의 클론이 기능이 알려진 유전자이었고, 그 중에서 1,442개는 생물학적인 대사에 관여하고 836개는 세포구성물과 관련이 있었다. EST와 contig의 평균 크기는 각각 702bp와 757bp이었다. 포도새눈무늬병균에 감염된 머루 cDNA library로부터 Proline-rich cell wall protein, thaumatin-like protein, class IV chitinase, and pathogenesis-related (PR) protein 10 등의 다양한 방어관련 유전자와 광합성관련유전자 및 수분스트레스 저항성 관련유전자가 많이 검출되었다. 본 연구를 통해 얻어진 머루의 EST 자료는 포도의 새로운 유전자원에 관한 연구 및 내병성 포도 신품종 육종 프로그램에 기본자료로 유용하게 활용될 것이다.

Rhynchium brunneum is a widely distributed wasp species in South Eastern Asia. R. brunneum females were collected from rural provinces of Cambodia, and their total RNA and venom were extracted on site. To search for novel substances in venom, a subtracted cDNA library specific to the venom gland and sac was constructed. A total of 1118 expressed sequenced sequence tags (ESTs) were sequenced and assembled into 349 contigs (107 multiple sequences and 242 singletons). In this result, we found the putative neurotoxin (DTX protein precursor), antimicrobial peptides (teratocyte-specific caboxylesterase) together with typical major components of wasp venom (venom hyaluronidase, arginine kinase, phospholipase A2, serine/theonine protein phosphatase). Additional in-depth annotation would be required for further characterization of many unidentified genes found in the EST library.

Perilla is a genus as a member of the mint family Lamiaceae which is known to contain lots of volatile metabolite. Perilla has been called as ‘deulkae’ indicating ‘wild sesame’ that means it has been maintained in Korea with long history. It has been very friendly used as edible oil and as fresh leaf vegetable. Perilla oil is valued for its medicinal benefit because it contains best amounts of unsaturated fatty acids, especially for the alpha-linolenic acid, known to omega-3 fatty acid, among all of the plant oils. It also include many beneficial phytochemicals. However, little study is conducted on their genetics. Here, we announce construction of well normalized and full length enriched-perilla cDNA library from a whole plant of one cultivar ‘Youngho-deulkae’ and their sequence characterization to provide useful resources for genetics, breeding and metabolite engineering. By sequencing of 5,760 cDNA clones, we 5,438 high quality EST sequences. Sequence trimming and assembly resulted 3,995 unigenes which consists 1,004 contigs and 2,991 singletones. Unigenes that showed little homology at the DNA sequence level with known genes in other plants even though they showed similarity at the protein domain level based on BLASTN, BLASTX, and TBLASTX. This study may provide good resources for initiation of further genomics, comparative genomics, functional genomics such as metabolic engineering and molecular breeding.