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The structure of the bacterial oxidoreductase enzyme DsbA in complex with a peptide reveals a basis for substrate specificity in the catalytic cycle of DsbA enzymes
Citation
Paxman, JJ and Borg, NA and Horne, HJ and Thompson, PE and Chin, Y and Sharma, P and Simpson, JS and Wielens, J and Piek, S and Kahler, CM and Sakellaris, H and Pearce, M and Bottomley, SP and Rossjohn, J and Scanlon, MJ, The structure of the bacterial oxidoreductase enzyme DsbA in complex with a peptide reveals a basis for substrate specificity in the catalytic cycle of DsbA enzymes, Journal of Biological Chemistry, 284, (26) pp. 17835-17845. ISSN 0021-9258 (2009) [Refereed Article]
DOI: doi:10.1074/jbc.M109.011502
Abstract
Oxidative protein folding in Gram-negative bacteria results in the
formation of disulfide bonds between pairs of cysteine residues. This is
a multistep process in which the dithiol-disulfide oxidoreductase
enzyme, DsbA, plays a central role. The structure of DsbA comprises an
all helical domain of unknown function and a thioredoxin domain, where
active site cysteines shuttle between an oxidized, substrate-bound,
reduced form and a DsbB-bound form, where DsbB is a membrane protein
that reoxidizes DsbA. Most DsbA enzymes interact with a wide variety of
reduced substrates and show little specificity. However, a number of
DsbA enzymes have now been identified that have narrow substrate
repertoires and appear to interact specifically with a smaller number of
substrates. The transient nature of the DsbA-substrate complex has
hampered our understanding of the factors that govern the interaction of
DsbA enzymes with their substrates. Here we report the crystal structure
of a complex between Escherichia coli DsbA and a peptide with a sequence
derived from a substrate. The binding site identified in the
DsbA-peptide complex was distinct from that observed for DsbB in the
DsbA-DsbB complex. The structure revealed details of the DsbA-peptide
interaction and suggested a mechanism by which DsbA can simultaneously
show broad specificity for substrates yet exhibit specificity for DsbB.
This mode of binding was supported by solution nuclear magnetic
resonance data as well as functional data, which demonstrated that the
substrate specificity of DsbA could be modified via changes at the
binding interface identified in the structure of the complex.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Research Division: | Biological Sciences |
| Research Group: | Biochemistry and cell biology |
| Research Field: | Structural biology (incl. macromolecular modelling) |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in the health sciences |
| UTAS Author: | Horne, HJ (Dr James Horne) |
| ID Code: | 79606 |
| Year Published: | 2009 |
| Web of Science® Times Cited: | 57 |
| Deposited By: | Central Science Laboratory |
| Deposited On: | 2012-09-24 |
| Last Modified: | 2015-02-02 |
| Downloads: | 0 |
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