Role of cysteine residues in the redox-regulated oligomerization and nucleotide binding to EhRabX3

Chandra, Mintu and Datta, Sunando (2016) Role of cysteine residues in the redox-regulated oligomerization and nucleotide binding to EhRabX3. Molecular and Biochemical Parasitology, 208 2: 84-90. doi:10.1016/j.molbiopara.2016.06.009


Author Chandra, Mintu
Datta, Sunando
Title Role of cysteine residues in the redox-regulated oligomerization and nucleotide binding to EhRabX3
Formatted title
Role of cysteine residues in the redox-regulated oligomerization and nucleotide binding to EhRabX3
Journal name Molecular and Biochemical Parasitology   Check publisher's open access policy
ISSN 1872-9428
0166-6851
Publication date 2016-08-01
Sub-type Article (original research)
DOI 10.1016/j.molbiopara.2016.06.009
Open Access Status Not yet assessed
Volume 208
Issue 2
Start page 84
End page 90
Total pages 7
Place of publication Amsterdam, Netherlands
Publisher Elsevier BV
Collection year 2017
Language eng
Formatted abstract
The enteric protozoan parasite, Entamoeba histolytica, an etiological agent of amebiasis, is involved in the adhesion and destruction of human tissues. Worldwide, the parasite causes about 50 million cases of amebiasis and 100,000 deaths annually. EhRabX3, a unique amoebic Rab GTPase with tandem G-domains, possesses an unusually large number of cysteine residues in its N-terminal domain. Crystal structure of EhRabX3 revealed an intra-molecular disulfide bond between C39 and C163 which is critical for maintaining the 3-dimensional architecture and biochemical function of this protein. The remaining six cysteine residues were found to be surface exposed and predicted to be involved in inter-molecular disulfide bonds. In the current study, using biophysical and mutational approaches, we have investigated the role of the cysteine residues in the assembly of EhRabX3 oligomer. The self-association of EhRabX3 is found to be redox sensitive, in vitro. Furthermore, the oligomeric conformation of EhRabX3 failed to bind and exchange the guanine nucleotide, indicating structural re-organization of the active site. Altogether, our results provide valuable insights into the redox-dependent oligomerization of EhRabX3 and its implication on nucleotide binding.
Keyword Cysteine
Inter-molecular disulfide bond
Intra-molecular disulfide bond
Oligomerization
Redox regulation
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Institute for Molecular Bioscience - Publications
 
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