The role of a disulfide bridge in the stability and folding kinetics of Arabidopsis thaliana cytochrome c(6A).

نویسندگان

  • Jody M Mason
  • Derek S Bendall
  • Christopher J Howe
  • Jonathan A R Worrall
چکیده

Cytochrome c(6A) is a eukaryotic member of the Class I cytochrome c family possessing a high structural homology with photosynthetic cytochrome c(6) from cyanobacteria, but structurally and functionally distinct through the presence of a disulfide bond and a heme mid-point redox potential of +71mV (vs normal hydrogen electrode). The disulfide bond is part of a loop insertion peptide that forms a cap-like structure on top of the core α-helical fold. We have investigated the contribution of the disulfide bond to thermodynamic stability and (un)folding kinetics in cytochrome c(6A) from Arabidopsis thaliana by making comparison with a photosynthetic cytochrome c(6) from Phormidium laminosum and through a mutant in which the Cys residues have been replaced with Ser residues (C67/73S). We find that the disulfide bond makes a significant contribution to overall stability in both the ferric and ferrous heme states. Both cytochromes c(6A) and c(6) fold rapidly at neutral pH through an on-pathway intermediate. The unfolding rate for the C67/73S variant is significantly increased indicating that the formation of this region occurs late in the folding pathway. We conclude that the disulfide bridge in cytochrome c(6A) acts as a conformational restraint in both the folding intermediate and native state of the protein and that it likely serves a structural rather than a previously proposed catalytic role.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Gene transcriptomic profile in arabidopsis thaliana mediated by radiation-induced bystander effects

Background: The in vivo radiation-induced bystander effects (RIBE) at the developmental, genetic, and epigenetic levels have been well demonstrated using model plant Arabidopsis thaliana (A. thaliana). However, the mechanisms underlying RIBE in plants are not clear, especially lacking a comprehensive knowledge about the genes and biological pathways involved in the RIBE in plants. Materials and...

متن کامل

Structural Characteristics of Stable Folding Intermediates of Yeast Iso-1-Cytochrome-c

Cytochrome-c (cyt-c) is an electron transport protein, and it is present throughout the evolution. More than 280 sequences have been reported in the protein sequence database (www.uniprot.org). Though sequentially diverse, cyt-c has essentially retained its tertiary structure or fold. Thus a vast data set of varied sequences with retention of similar structure and fun...

متن کامل

Negative control of Strictisidine synthase like-7 gene on salt stress resistance in Arabidopsis thaliana

Strictosidine synthase-like (SSL) is a group of gene families in the Arabidopsis genome, which whose orthologues in other plants are key enzymes in mono-terpenoid indole-alkaloid biosynthesis pathway. The SSL7 is upregulated upon treatments of Arabidopsis plants with signaling molecules such as SA, methyl jasmonate and ethylene. To find the functional role of the gene, a T-DNA-mediated knockout...

متن کامل

Functional analysis of glycin rich- RNA binding protein, a suppressor of trehalose-6-phosphate mediating growth arrest in Arabidopsis thaliana

Metabolism of the alpha-1,1 glucose disaccharide, trehalose, is indispensable in plants. In the Murashigeand Skoog (MS) medium, trehalose inhibits plant growth and allocation of carbon to roots. A suppressorof trehalose-6-phosphate (T6P) mediated growth arrest, GR-RBP2, is characterized in more detail.Phylogenetic analysis revealed that GR-RBP2 is a protein of likely prokaryot...

متن کامل

مشکلات روش‌های موجود و ارائه دو روش جدید کشت هیدروپونیک گیاه آرابیدوپسیس تالیانا

Arabidopsis thaliana is a suitable model plant for genetic and molecular biology studies in higher plants. However, its hydroponic culture for biochemical and physiological studies is a challenge due to small size, capillary roots and little biomass at maturity. Several cultural systems have been suggested for Arabidopsis thaliana hydroponic culture, each having special advantages and disadvant...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Biochimica et biophysica acta

دوره 1824 2  شماره 

صفحات  -

تاریخ انتشار 2012