Dynamics in transient complexes of redox proteins

Ubbink, Marcellus

doi:10.1042/bst20110698

Cited by 32 publications

(38 citation statements)

References 20 publications

(24 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar complexes were observed in a number of electron transfer protein systems, including cyt b 5 -cyt P450 (22,58), adrenodoxin-cyt c (44), myoglobin-cyt b 5 (23), cyt c-cyt b 5 (24,43), and plastocyanin-cyt f complexes (59). Dynamic complexes are usually formed between two proteins rich in complementary charges and dominantly driven by long-range electrostatic interactions (57). Most of the orientations involved in dynamic complexes are not optimized to facilitate interprotein electron transfer.…”

Section: Comparison Of Cyt C Reduction By Fbd and Full-lengthmentioning

confidence: 81%

“…Electron transfer between one electron-reduced CPR and cyt c is most likely prohibited due to the "closed" conformation of CPR, whereas cyt c reduction by two electron-reduced CPR is likely to be gated by domain movement of the protein. Complex Formation between FBD and Cyt c-It has been proposed that weak and transient complexes are commonly formed between electron transfer proteins to ensure high turnover rates (57). The relative orientation of the two proteins in the complex can range from well defined to highly dynamic (44).…”

Section: Comparison Of Cyt C Reduction By Fbd and Full-lengthmentioning

confidence: 99%

See 1 more Smart Citation

Kinetic and Structural Characterization of the Interaction between the FMN Binding Domain of Cytochrome P450 Reductase and Cytochrome c

Huang

Zhang

Rwere

et al. 2015

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

Section: Comparison Of Cyt C Reduction By Fbd and Full-lengthmentioning

confidence: 81%

Section: Comparison Of Cyt C Reduction By Fbd and Full-lengthmentioning

confidence: 99%

Kinetic and Structural Characterization of the Interaction between the FMN Binding Domain of Cytochrome P450 Reductase and Cytochrome c

Huang

Zhang

Rwere

et al. 2015

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…1,5 Interprotein ET reactions carry a particularly stringent requirement for fast intermolecular association and turnover. Indeed, the functional importance of encounter complexes in interprotein ET reactions has been well documented in several redox pairs such as cytochrome c (cyt c )–cyt c peroxidase, 6–8 cyt b 5 –myoglobin, 9,10 and cyt f –plastocyanin. 11–13 In this work, we establish that the complex interprotein ET interactions in the metalloenzyme nitrogenase also involve functionally relevant encounter complexes, whose active role in nitrogenase catalysis has previously been only postulated.…”

Section: Introductionmentioning

confidence: 99%

Evidence for Functionally Relevant Encounter Complexes in Nitrogenase Catalysis

et al. 2015

View full text Add to dashboard Cite

Nitrogenase is the only enzyme that can convert atmospheric dinitrogen (N2) into the biologically usable ammonia. To achieve this multi-electron redox process, the nitrogenase component proteins, MoFe-protein (MoFeP) and Fe-protein (FeP), repeatedly associate and dissociate in an ATP dependent manner, where one electron is transferred from FeP to MoFeP per association. Here, we provide evidence for the first time that encounter complexes between FeP and MoFeP play a functional role in nitrogenase turnover. The encounter complexes are stabilized by electrostatic interactions involving a positively charged patch on the β-subunit of MoFeP. Three single mutations (βAsn399Glu, βLys400Glu, and βArg401Glu) in this patch were generated in Azotobacter vinelandii MoFeP. All of the resulting variants displayed decreases in specific catalytic activity, with the βK400E mutation showing the largest effect. As simulated by the Thorneley-Lowe kinetic scheme, this single mutation lowered the rate constant for FeP-MoFeP association five-fold. We also found that the βK400E mutation did not affect the coupling of ATP hydrolysis with electron transfer (ET) between FeP and MoFeP. These data suggest a mechanism where FeP initially forms encounter complexes on the MoFeP β-subunit surface en route to the ATP-activated, ET-competent complex over the αβ-interface.

show abstract

“…However, a number of studies in solution have made clear that encounter states are an inherent element of protein complexes (1)(2)(3)(4)(5)(6)(7)(8), especially in electron transfer (ET), where the interactions are often extremely fast (9). In the encounter complex, the proteins assume multiple other orientations, often in equilibrium with the major stereospecific state.…”

mentioning

confidence: 99%

Identification of productive and futile encounters in an electron transfer protein complex

Andrałojć

Hiruma

Wei-min

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Well-defined, stereospecific states in protein complexes are often in exchange with an ensemble of more dynamic orientations: the encounter states. The structure of the stereospecific complex between cytochrome P450cam and putidaredoxin was solved recently by X-ray diffraction as well as paramagnetic NMR spectroscopy. Other than the stereospecific complex, the NMR data clearly show the presence of additional states in the complex in solution. In these encounter states, populated for a small percentage of the time, putidaredoxin assumes multiple orientations and samples a large part of the surface of cytochrome P450cam. To characterize the nature of the encounter states, an extensive paramagnetic NMR dataset has been analyzed using the Maximum Occurrence of Regions methodology. The analysis reveals the location and maximal spatial extent of the additional states needed to fully explain the NMR data. Under the assumption of sparsity of the size of the conformational ensemble, several minor states can be located quite precisely. The distribution of these minor states correlates with the electrostatic potential map around cytochrome P450cam. Whereas some minor states are on isolated positively charged patches, others are connected to the stereospecific site via positively charged paths. The existence of electrostatically favorable pathways between the stereospecific interaction site and the different minor states or lack thereof suggests a means to discriminate between productive and futile encounter states.paramagnetic NMR | encounter complex | cytochrome P450cam | putidaredoxin | maximum occurrence C rystal structures suggest that proteins assume unique, stereospecific orientations within protein-protein complexes. However, a number of studies in solution have made clear that encounter states are an inherent element of protein complexes (1-8), especially in electron transfer (ET), where the interactions are often extremely fast (9). In the encounter complex, the proteins assume multiple other orientations, often in equilibrium with the major stereospecific state. In low-affinity complexes with dissociation constant (K d ) values > 10 μM, the encounter complex can represent a sizeable fraction, and in some cases, a well-defined, stereospecific complex may even be absent (10-15). The presence of encounter states may be a consequence of the chemical nature of proteins. In nonobligate stereospecific complexes, the interface represents a small fraction of the total protein surface, and therefore, it is reasonable to assume that weak interactions also occur elsewhere. In the case in which protein pairs have evolved to exhibit a high association rate by using electrostatic preorientation, electrostatic patches seem to enhance the presence of encounter states (16,17). On the one hand, the preorientation reduces the surface area that is visited by the partner, thus enhancing the number of productive encounters, but on the other hand, highly charged patches can bind the oppositely charged protein in many orientations with a...

show abstract

Dynamics in transient complexes of redox proteins

Cited by 32 publications

References 20 publications

Kinetic and Structural Characterization of the Interaction between the FMN Binding Domain of Cytochrome P450 Reductase and Cytochrome c

Kinetic and Structural Characterization of the Interaction between the FMN Binding Domain of Cytochrome P450 Reductase and Cytochrome c

Evidence for Functionally Relevant Encounter Complexes in Nitrogenase Catalysis

Identification of productive and futile encounters in an electron transfer protein complex

Contact Info

Product

Resources

About