Macrina F L, Jones K R, Laloi P
Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond 23298-0678, USA.
Plasmid. 1996 Jul;36(1):9-18. doi: 10.1006/plas.1996.0026.
The complete nucleotide sequence of the insertion sequence IS199 has been determined. This novel element was found in Streptococcus mutans V403 where DNA hybridization studies suggested that it was present in multiple copies on the genome. IS199 is 1220 bp and appears unique to the mutans streptococci. A limited epidemiological survey revealed this element to occur infrequently in this group (4/50 strains examined). IS199 belongs to the IS3 family of procaryotic insertion sequence elements. It contained tandem open reading frames (ORFs) reminiscent of the structure of the IS3 class. Additionally, the larger of the two ORF products (ORFB) exhibited amino acid sequence similarities to comparable proteins from IS3 and other elements of this family. Transposition of IS199 gave rise to a 3-bp target site duplication. We were able to insert an antibiotic resistance gene into IS199 enabling us to follow the transposition of this element in S. mutans V403.
插入序列IS199的完整核苷酸序列已被确定。这种新元件是在变形链球菌V403中发现的，DNA杂交研究表明它在基因组中以多拷贝形式存在。IS199为1220碱基对，在变形链球菌中似乎是独特的。一项有限的流行病学调查显示，该元件在这一组中出现的频率较低（在所检测的50株菌株中有4株）。IS199属于原核生物插入序列元件的IS3家族。它包含串联开放阅读框（ORF），这让人联想到IS3类的结构。此外，两个ORF产物中较大的那个（ORFB）与来自IS3和该家族其他元件的可比蛋白质表现出氨基酸序列相似性。IS199的转座产生了一个3碱基对的靶位点重复。我们能够将一个抗生素抗性基因插入IS199，从而能够追踪该元件在变形链球菌V403中的转座情况。
