title: The C-terminal zinc finger domain of Arabidopsis cold shock domain proteins is important for RNA chaperone activity during cold adaptation.
abstract: Among the four cold shock domain proteins (CSDPs) identified in Arabidopsis thaliana, it has recently been shown that CSDP1 harboring seven CCHC-type zinc fingers, but not CSDP2 harboring two CCHC-type zinc fingers, function as a RNA chaperone during cold adaptation. However, the structural features relevant to this differing RNA chaperone activity between CSDP1 and CSDP2 remain largely unknown. To determine which structural features are necessary for the RNA chaperone activity of the CSDPs, the importance of the N-terminal cold shock domain (CSD) and the C-terminal zinc finger glycine-rich domains of CSDP1 and CSDP2 were assessed. The results of sequence motif-swapping and deletion experiments showed that, although the CSD itself harbored RNA chaperone activity, the number and length of the zinc finger glycine-rich domains of CSDPs were crucial to the full activity of the RNA chaperones. The C-terminal domain itself of CSDP1, harboring seven CCHC-type zinc fingers, also has RNA chaperone activity. The RNA chaperone activity and nuclei acid-binding property of the native and chimeric proteins were closely correlated with each other. Collectively, these results indicate that a specific modular arrangement of the CSD and the zinc finger domain determines both the RNA chaperone activity and nucleic acid-binding property of CSDPs; this, in turn, contributes to enhanced cold tolerance in plants as well as in bacteria.
authors.affiliation: Department of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, Republic of Korea.
authors.forename: Su Jung
authors.initials: SJ
authors.lastname: Park
authors.forename: Kyung Jin
authors.initials: KJ
authors.lastname: Kwak
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Jung
authors.forename: Hwa Jung
authors.initials: HJ
authors.lastname: Lee
authors.forename: Hunseung
authors.initials: H
authors.lastname: Kang
mesh_terms: D000064:Acclimatization / Q000235:genetics*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics; D057773:Cold Shock Proteins and Peptides; D003080:Cold Temperature; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D006360:Heat-Shock Proteins / Q000737:chemistry; D018832:Molecular Chaperones / Q000737:chemistry*; D012313:RNA / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D013329:Structure-Activity Relationship; D016335:Zinc Fingers
chemical_list: D029681:Arabidopsis Proteins; C517509:CSDP1 protein, Arabidopsis; D057773:Cold Shock Proteins and Peptides; D004268:DNA-Binding Proteins; C521041:GRP2 protein, Arabidopsis; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D016601:RNA-Binding Proteins; D012313:RNA