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Novel structural arrangement of nematode cystathionine β-synthases: characterization of Caenorhabditis elegans CBS-1
- Source :
- Biochemical Journal
- Publication Year :
- 2012
- Publisher :
- Portland Press Ltd., 2012.
-
Abstract
- CBSs (cystathionine β-synthases) are eukaryotic PLP (pyridoxal 5 *-phosphate)-dependent proteins that maintain cellular homocysteine homoeostasis and produce cystathionine and hydrogen sulfide. In the present study, we describe a novel structural arrangement of the CBS enzyme encoded by the cbs-1 gene of the nematode Caenorhabditis elegans. The CBS-1 protein contains a unique tandem repeat of two evolutionarily conserved catalytic regions in a single polypeptide chain. These repeats include a catalytically active C-terminal module containing a PLP-binding site and a less conserved N-terminal module that is unable to bind the PLP cofactor and cannot catalyse CBS reactions, as demonstrated by analysis of truncated variants and active-site mutant proteins. In contrast with other metazoan enzymes, CBS-1 lacks the haem and regulatory Bateman domain essential for activation by AdoMet (S-adenosylmethionine) and only forms monomers. We determined the tissue and subcellular distribution of CBS-1 and showed that cbs-1 knockdown by RNA interference leads to delayed development and to an approximately 10-fold elevation of homocysteine concentrations in nematode extracts. The present study provides the first insight into the metabolism of sulfur amino acids and hydrogen sulfide in C. elegans and shows that nematode CBSs possess a structural feature that is unique among CBS proteins.
- Subjects :
- Models, Molecular
Cytoplasm
AdoMet, S-adenosylmethionine
domain architecture
Mutant
hydrogen sulfide
BN, blue native
Biochemistry
0302 clinical medicine
RNA interference
Homeostasis
LC–MS/MS, liquid chromatography–tandem MS
Homocysteine
Conserved Sequence
Caenorhabditis elegans
GFP, green fluorescent protein
chemistry.chemical_classification
0303 health sciences
RT, reverse transcription
biology
cystathionine β-synthase (CBS)
knockdown
UTR, untranslated region
RNAi, RNA interference
Organ Specificity
EST, expressed sequence tag
Research Article
inorganic chemicals
congenital, hereditary, and neonatal diseases and abnormalities
SEC, size-exclusion chromatography
Molecular Sequence Data
BS3, bis(sulfosuccinimidyl) suberate
Cystathionine beta-Synthase
Cofactor
03 medical and health sciences
Tandem repeat
Animals
Humans
Amino Acid Sequence
Protein Structure, Quaternary
CBS, cystathionine β-synthase
Molecular Biology
Gene
030304 developmental biology
organic chemicals
nutritional and metabolic diseases
Cell Biology
biology.organism_classification
WT, wild-type
Cystathionine beta synthase
Protein Structure, Tertiary
CGL, cystathionine γ-lyase
Enzyme
chemistry
DTT, dithiothreitol
Biocatalysis
biology.protein
Sequence Alignment
PLP, pyridoxal 5*-phosphate
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 14708728 and 02646021
- Volume :
- 443
- Database :
- OpenAIRE
- Journal :
- Biochemical Journal
- Accession number :
- edsair.doi.dedup.....96f94960daa5aa3b85aadddb2dd82ea4