Streptococcus Thermophilus 231-X10 Fajinin Kismi̇ Genomi̇k Karakteri̇zasyonu

Abstract

ÖzetBu çal›flmada, daha önce yap›lm›fl çal›flmalarla morfolojik olarak tan›mlanm›fl, konakç› spektrumu ve yap›sal proteinleri belirlenmifl, restriksiyon fragment analizleri yap›lm›fl 231-X10 faj›n›n belirli bir genom bölgesinin dizi analizi yap›lm›flt›r. Dizi analizi yap›lm›fl olan bu bölgede 13 adet aç›k okuma çerçevesinin yani 13 farkl› fonksiyonu kodlayan gen bölgesinin olabilece¤i ortaya ç›kar›lm›flt›r. Bu gen bölgelerinin faj DNA's›n›n replikasyonu, DNA'n›n paketlenmesi, kapsid ve kuyruk yap›s›n›n oluflumundan sorumlu proteinleri kodlad›¤› belirlenmifltir. 231-X10 faj›na ait bu genom bölgesi taraf›ndan kodlanan proteinlerin aminoasit baz›nda cos-tipi DNA paketleme mekanizmas›na sahip fajlarla yüksek benzerlik gösterdi¤i tespit edilmifl ve dolay›s›yla bu faj›n da cos-tipi olabilece¤i sonucuna var›lm›flt›r. Yap›lan bu incelemeler sonucunda S. thermophilus fajlar›n›n ortak bir atadan geldi¤i, nokta mutasyonlar, küçük eklemeler ve kay›plar ile evrimlefltikleri düflüncesi desteklenmifltir. Anahtar kelimeler: S. thermophilus faj›, dizi analizi, genomik organizasyon PARTIAL GENOMIC CHARACTERIZATION OF STREPTOCOCCUS THERMOPHILUS PHAGE 231-X10 AbstractIn this study, the partial genomic sequencing of S. thermophilus 231-X10 phage was carried out. 231-X10 was identified morphologically, and its host spectrum, structural proteins and restriction analysis have also been completed in previous studies. Thirteen different open reading frames that was coded by thirteen genes were detected in that partial genome. These genes are responsible for DNA replication, DNA packaging and the formation of capsid and tail structure. The proteins that are encoded by the genomic region of 231-X10 phage have been found to show high similarities between the phages which have cos-type DNA packaging mechanism on the basis of amino acids. Thus, it is concluded that the 231-X10 phage might also be cos-type. As a result of these investigations, it is supported the idea that S. thermophilus phages come from a common ancestor and evolved with point mutations, small additions and deletions.