The Conserved Active Site Proline Determines the Reducing Power of Staphylococcus aureus Thioredoxin

Roos, Goedele; García-Pino, Abel; Belle, Karolien Van; Brosens, Elke; Wahni, Khadija; Vandenbussche, Guy; Wyns, Lode; Loris, Remy; Messens, Joris

doi:10.1016/j.jmb.2007.02.045

Cited by 69 publications

(83 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results are analogous to the calculations with a model of wild type Trx, and thus within the structural environment of wild type Trx, Trp28 has no effect on reactivity, regioselectivity and on the pKa of Cys29 Trx . As such, the experimentally obtained results 5,6 of an increased pKa of Cys29 Trx and a decreased redox potential in Trx W28A most likely originates form the structural effects induced by the partial unfolding of Trx W28A.…”

Section: Resultsmentioning

confidence: 92%

“…6 They seem to be partially unfolded, reminiscent to a molten globule-like population. 6 We previously showed that the pKa of Cys29 increases from 7.1 in wild type Trx to 8.3 in the monomeric form of Trx W28A, 5 which is a pKa value more similar to the pKa of a cysteine out of its structural environment. Further, in Trx W28A, the redox potential decreases from À268 mV to À284 mV.…”

Section: Introductionmentioning

confidence: 97%

“…1 All Trx feature a conserved active-site loop with a Trp-Cys-Gly-Pro-Cys 2-4 sequence motif, numbered as Trp28 to Cys32 in Staphylococcus aureus Trx (Trx). In the structure of S. aureus Trx (2O7K), 5 the indole side chain of Trp28 is turned towards the interior of the protein and covers an important part of the active side. There are no direct hydrogen bond interactions of Trp28 with the catalytic active cysteine residues.…”

Section: Introductionmentioning

confidence: 99%

“…Further, in Trx W28A, the redox potential decreases from À268 mV to À284 mV. 5 It is not known whether these effects are due to conformational changes induced by the partially unfolding of the Trx W28A mutant or due to the absence of the conserved tryptophan indole side chain as possible interacting partner for the nucleophilic cysteines in the active site. It is not possible to exclude one of the possibilities experimentally, because upon the introduction of the Trp28Ala mutation, Trx shows the tendency to partially unfold.…”

Section: Introductionmentioning

confidence: 99%

“…It is not possible to exclude one of the possibilities experimentally, because upon the introduction of the Trp28Ala mutation, Trx shows the tendency to partially unfold. 5 Therefore, theoretical pKa calculations and density functional theory (DFT) [7][8][9] reactivity analysis on model systems with Trp28 replaced by alanine within the structural environment of wild type Trx are used to give insight in the intrinsic role of Trp28 on the redox behavior of Trx.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

The conserved active site tryptophan of thioredoxin has no effect on its redox properties

Roos¹,

Geerlings²,

Messens³

2009

Protein Science

Self Cite

View full text Add to dashboard Cite

In Staphylococcus aureus thioredoxin (Trx) it has been shown that mutation of the conserved active site tryptophan residue (Trp28) has a large effect on the protein stability, on the pKa of the nucleophilic cysteine and on the redox potential. Since these effects can either be due to the partially unfolding of the Trp28Ala mutant or to the absence of the indole side chain of Trp28 as possible interaction partner for the active site cysteines, the origin of the experimentally observed effects is not known and is beyond experimental approach. With theoretical pKa and density functional theory reactivity analysis on model systems where Trp28 has been replaced by an alanine within the structural environment of Trx it is shown that Trp28 does not affect the redox parameters of Trx. As such, the experimentally observed redox effects of the Trx W28A mutant might be due to structural changes induced by partial unfolding.

show abstract

Section: Resultsmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

The conserved active site tryptophan of thioredoxin has no effect on its redox properties

Roos¹,

Geerlings²,

Messens³

2009

Protein Science

Self Cite

View full text Add to dashboard Cite

show abstract

Placodal sensory ganglia coordinate the formation of the cranial visceral motor pathway

Takano-Maruyama

Chen

Gaufo

2010

Developmental Dynamics

View full text Add to dashboard Cite

The parasympathetic reflex circuit is controlled by three basic neurons. In the vertebrate head, the sensory, and pre-and postganglionic neurons that comprise each circuit have stereotypic positions along the anteroposterior (AP) axis, suggesting that the circuit arises from a common developmental plan. Here, we show that precursors of the VIIth circuit are initially aligned along the AP axis, where the placodederived sensory neurons provide a critical ''guidepost'' through which preganglionic axons and their neural crest-derived postganglionic targets navigate before reaching their distant target sites. In the absence of the placodal sensory ganglion, preganglionic axons terminate and the neural crest fated for postganglionic neurons undergo apoptosis at the site normally occupied by the placodal sensory ganglion. The stereotypic organization of the parasympathetic cranial sensory-motor circuit thus emerges from the initial alignment of its precursors along the AP axis, with the placodal sensory ganglion coordinating the formation of the motor pathway.

show abstract

Unifying mechanical and thermodynamic descriptions across the thioredoxin protein family

Mottonen

Jacobs

et al. 2008

Proteins

View full text Add to dashboard Cite

We compare various predicted mechanical and thermodynamic properties of nine oxidized thioredoxins (TRX) using a Distance Constraint Model (DCM). The DCM is based on a nonadditive free energy decomposition scheme, where entropic contributions are determined from rigidity and flexibility of structure based on distance constraints. We perform averages over an ensemble of constraint topologies to calculate several thermodynamic and mechanical response functions that together yield quantitative stability/flexibility relationships (QSFR). Applied to the TRX protein family, QSFR metrics display a rich variety of similarities and differences. In particular, backbone flexibility is well conserved across the family, whereas cooperativity correlation describing mechanical and thermodynamic couplings between residue pairs exhibit distinctive features that readily standout. The diversity in predicted QSFR metrics that describe cooperativity correlation between pairs of residues is largely explained by a global flexibility order parameter describing the amount of intrinsic flexibility within the protein. A free energy landscape is calculated as a function of the flexibility order parameter, and key values are determined where the native-state, transition-state and unfolded-state are located. Another key value identifies a mechanical transition where the global nature of the protein changes from flexible to rigid. The key values of the flexibility order parameter help characterize how mechanical and thermodynamic response is linked. Variation in QSFR metrics, and key characteristics of global flexibility are related to the native state x-ray crystal structure primarily through the hydrogen bond network. Furthermore, comparison of three TRX redox pairs reveals differences in thermodynamic response (i.e., relative melting point) and mechanical properties (i.e., backbone flexibility and cooperativity correlation) that are consistent with experimental data on thermal stabilities and NMR dynamical profiles. The results taken together demonstrate that small-scale structural variations are amplified into discernible global differences by propagating mechanical couplings through the H-bond network.

show abstract

The Conserved Active Site Proline Determines the Reducing Power of Staphylococcus aureus Thioredoxin

Cited by 69 publications

References 46 publications

The conserved active site tryptophan of thioredoxin has no effect on its redox properties

The conserved active site tryptophan of thioredoxin has no effect on its redox properties

Placodal sensory ganglia coordinate the formation of the cranial visceral motor pathway

Unifying mechanical and thermodynamic descriptions across the thioredoxin protein family

Contact Info

Product

Resources

About