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Functional implications of the proximal site hydrogen bonding network in Vitreoscilla hemoglobin (VHb): role of Tyr95 (G5) and Tyr126 (H12).

IR@IMTECH: CSIR-Institute of Microbial Technology, Chandigarh

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Title Functional implications of the proximal site hydrogen bonding network in Vitreoscilla hemoglobin (VHb): role of Tyr95 (G5) and Tyr126 (H12).
 
Creator Kaur, Ramandeep
Ahuja, Sandhya
Anand, Arvind
Singh, Balvinder
Stark, Benjamin C
Webster, Dale A
Dikshit, Kanak L
 
Subject QR Microbiology
 
Description Although Vitreoscilla hemoglobin (VHb) carries a conventional globin fold, its proximal site geometry is unique in having a hydrogen-bonding network between proximal site residues, HisF8-TyrG5-GluH23 and TyrG5-TyrH12. TyrG5 and TyrH12 were mutated to study their relevance in VHb function. VHb G5 mutants (Tyr95Phe and Tyr95Leu showed no stable oxyform and nitric oxide dioxygenase activity, whereas, VHb H12 mutants (Tyr126Phe and Tyr126Leu) displayed little change in their oxygen affinity indicating a crucial role of Tyr95 in protein function. The VHb H12 mutant, Tyr126Leu, enhanced the intracellular pool of oxygen and cell growth better than VHb. Molecular modeling suggests that the replacement of tyrosine with leucine in Tyr126Leu creates an opening on the protein surface that may facilitate oxygen diffusion and accumulation.
 
Publisher Elsevier Science
 
Date 2008-10-15
 
Type Article
PeerReviewed
 
Format application/pdf
 
Identifier http://crdd.osdd.net/open/581/1/dikshit08.1.pdf
Kaur, Ramandeep and Ahuja, Sandhya and Anand, Arvind and Singh, Balvinder and Stark, Benjamin C and Webster, Dale A and Dikshit, Kanak L (2008) Functional implications of the proximal site hydrogen bonding network in Vitreoscilla hemoglobin (VHb): role of Tyr95 (G5) and Tyr126 (H12). FEBS letters, 582 (23-24). pp. 3494-500. ISSN 0014-5793
 
Relation http://www.sciencedirect.com/science/article/pii/S0014579308007515
http://crdd.osdd.net/open/581/