Sequence analysis of a Staphylococcus aureus gene encoding a peptidoglycan hydrolase activity.

The nucleotide (nt) sequence of a 2.0-kb NheI-XbaI DNA fragment containing a peptidoglycan hydrolase-encoding gene, lytA, tentatively identified as encoding an N-acetylmuramyl-L-alanine amidase, from Staphylococcus aureus, was determined. The nt sequencing revealed an open reading frame (ORF) of 1443 bp with a consensus ribosome-binding site located 7 nt upstream from the ATG start codon. The primary amino acid (aa) sequence deduced from the nt sequence revealed a putative protein of 481 aa residues with an Mr of 53815. Comparison of the aa sequence of the ORF with aa sequences in the GenBank data base (version 63, March 1990) revealed that the C-terminal sequence showed significant homology to the C-terminal sequence of lysostaphin from Staphylococcus simulans biovar staphylolyticus.     

圈卷产色链霉菌尼可霉素生物合成基因-sanK的克隆及功能研究

利用染色体步移策略,以尼可霉素生物合成相关的基因片段为探针,从圈卷产色链霉菌中克隆到了一个大约１０ｋｂ的ＤＮＡ片段。对其中１．８ｋｂ的ＰｖｕⅡ－ＳａｃⅡ片段进行了序列分析,结果表明：此片段中含有一个具有１１７０个核苷酸的完整开放阅读框,起始密码子为４４７位的ＡＴＧ,终止密码子为１６１４位的ＴＧＡ,推测其编码一个３８９个氨基酸的蛋白质产物。利用ＢＬＡＳＴＸ程序进行了分析揭示,此基因编码一个肌氨酸单体     

Nucleotide sequence of the gene presumably encoding the adsorption protein of filamentous phage φLf

A 1170-nucleotide fragment of φLf DNA was sequenced. This fragment contains an open reading frame, ORF367, encoding a protein of 367 amino acids (aa) (36710 Da). ORF367 is located downstream from the gene encoding the major coat protein (gVIIIp) and a Rho-independent termination signal. Sequence analysis revealed that the gene product has a Gly-rich domain (70 aa) at the center and a hydrophobic region (26 aa) at the C terminus. These structural features suggest that ORF367 may encode the adsorption protein of φLf.     

Characterization of the ksgA gene of Escherichia coli determining kasugamycin sensitivity

In the plasmid pUC8ksgA7, the coding region of the ksgA gene is preceded by the lac promoter (Plac) and a small open reading frame (ORF). This ORF of 15 codons is composed of nucleotides derived from the lacZ gene, a multiple cloning site and the ksgA gene itself. The reading frame begins with the ATG initiation codon of lacZ and ends a few nucleotides beyond the ATG start codon of ksgA. The ksgA gene is not preceded by a Shine-Dalgarno (SD) signal. Cells transformed with pUC8ksgA7 produce active methylase, the product of the ksgA gene. Introduction of an in-phase TAA stop codon in the small ORF abolishes methylase production in transformed cells. On the plasmid pUC8ksgA5, which contains the entire ksgA region, the promoter of the ksgA gene was found to reside in a 380 base pair Bgl1-Pvu2 restriction fragment, partly overlapping the ksgA gene, by two independent methods. Cloning of this fragment in front of the galK gene in plasmid pKO1 stimulates galactokinase activity in transformants and its insertion into the expression vector pKL203 makes beta-galactosidase synthesis independent of the presence of Plac. The sequence of the Bgl1-Pvu2 fragment was determined and a putative promoter sequence identified. An SD signal could not be distinguished at a proper distance upstream from the ksgA start codon. Instead, an ORF of 13 codons starting with ATG in tandem with an SD signal and ending 4 codons ahead of the ksgA gene was identified. This suggests that translation of the ORF is required for expression of the ksgA gene.(ABSTRACT TRUNCATED AT 250 WORDS)