Knockout and functional analysis of two DExD/H-box family helicase genes in Sulfolobus islandicus REY15A.
DExD/H-box helicases represent the largest family of helicases. They belong to superfamily 2 helicases and participate in nucleotide metabolism, ribosome biogenesis, and nucleocytoplasmic transport. The biochemical properties and structures of some DExD/H-box helicases in the archaea have been documented, but many of them have not been characterized; and reports on in vivo functional analyses are limited. In this study, we attempted gene knockout of 8 putative DExD/H-box helicases in Sulfolobus islandicus REY15A and obtained two deletion mutants, SiRe_0681 and SiRe_1605. We determined that ΔSiRe_0681 grew faster than wild type cells in the presence of methyl methanesulfonate (MMS). Flow cytometry analysis showed that this strain had fewer G1/S phase cells than the wild type, and the genes coding for cell division proteins were up-regulated. The stain ΔSiRe_1605 was more sensitive to MMS than the wild type cell, and many nucleotide metabolism and DNA repair enzymes were found to be down-regulated. Intriguingly, deletion of either gene led to silencing simultaneously of over 80 genes located at a specific region. This study provides a novel insight into the in vivo functions of predicted DExD/H-box family helicases in the archaea.
State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China.
Xueguo
X
Song
State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China.
Qihong
Q
Huang
State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China.
Jinfeng
J
Ni
State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China.
Yang
Y
Yu
State Key Laboratory of Microbial Technology, Shandong University, 27 Shanda Nan Rd., Jinan, 250100, China. yulgshen@sdu.edu.cn.
Yulong
Y
Shen
D019843:Archaeal Proteins / Q000235:genetics* / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase; D017353:Gene Deletion; D016944:Sulfolobus / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D019843:Archaeal Proteins; D018797:Cell Cycle Proteins; D004265:DNA Helicases; D045643:DNA Repair Enzymes
Archaea; DExD/H-box helicases; Gene knockout; In vivo functions; Sulfolobus islandicus REY15A