Zinc-substituted rubredoxin from the hyperthermophile, pyrococcus furiosus: Structural studies by 2D NMR.

Blake, Paul R.; Park, J.; Howard, James B.; Adams, Michael W. W.; Summers, M.F.

doi:10.1016/0162-0134(91)84237-4

Cited by 1 publication

(4 citation statements)

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“…The predominant structural mechanism by which zinc finger cores are screened is through networks of backbone:core NH-S hydrogen bonds, which also stabilize the local protein fold of zinc fingers. 36,37 This finding is consistent with the notion of a secondary NH-S "coordination shell" in the region of zinc finger cores. 38 Although only the electrostatic component of NH-S interactions has been evaluated, the results suggest charge-transfer and polarization components may make important contributions to the oxidative stability of zinc cores.…”

Section: Discussionsupporting

confidence: 89%

“…Although CH-S hydrogen bonds are substantially weaker than NH-S interactions, scalar coupling between aliphatic side chains and Fe Cys 4 cores has been proposed as a possible electron-transfer mechanism in rubredoxins. 36 If rubredoxin is excluded from the data, the statistical dissimilarity between F phobe profiles of Cys 2 -His 2 , compared to Cys 3 His (p 1/2 ) 0.04) and Cys 4 (p 1/2 ) 0.003), is well separated. In contrast, the F phobe profiles of Cys 4 and Cys 3 His are quite similar (p 1/2 ) 0.4).…”

Section: Resultsmentioning

confidence: 98%

“…Within proteins, amide backbone:core NH-S hydrogen bonds are often observed to electronically stabilize core thiolates, even in the case of neutral Cys 2 His 2 cores. [34][35][36] This network of NH-S bonds is also important for determining the local protein fold, as well as its overall stability. 36,37 Positively charged Arg and Lys side chains can also form ionic pairs with anionic cores, 38 similar to salt-bridges.…”

Section: Introductionmentioning

confidence: 99%

“…[34][35][36] This network of NH-S bonds is also important for determining the local protein fold, as well as its overall stability. 36,37 Positively charged Arg and Lys side chains can also form ionic pairs with anionic cores, 38 similar to salt-bridges. Notably, the Cys protonation state of zinc cores, under physiological conditions, remains unresolved.…”

Section: Introductionmentioning

confidence: 99%

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Reactivity of Zinc Finger Cores: Analysis of Protein Packing and Electrostatic Screening

2001

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The chemical stability of 207 zinc fingers, derived from 92 experimental protein structures, is evaluated according to the protein packing and electrostatic screening of their zinc cores. These properties are used as measures of the protein protection of zinc cores, to predictively rank relative zinc finger reactivities and assess differences in function. On average, there is a substantial and concomitant increase in the screening of increasingly anionic core motifs, suggesting zinc fingers have evolved in a manner that promotes shielding of their potentially reactive core thiolates. In contrast, enzymatic zinc cores are functionally differentiated by negative electrostatic screening. Zinc finger cores are predominantly screened by networks of backbone:core NH-S hydrogen bonds that electronically stabilize core thiolates and enhance backbone packing. Stabilizing protein:core interactions can be mapped to conserved residues, including [Arg,Lys]:core salt-bridges in some protein families. Labile zinc fingers are identified by poorly screened cores, possibly indicating redox or metallothionein (MT) regulated function. Consistent with experiment, the cores of the C-terminal finger of the human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein p7 (NCp7) and Escherichia coli Ada protein (Ada) "finger" are identified as reactive. The C-terminal zinc fingers of nuclear receptors are predicted to be the most labile in this study, particularly the human estrogen receptor (hER), which contains a triad of reactive thiolates. We propose that hER DNA binding is redox and MT regulated through the C-terminal finger and that weak electrophilic agents may inhibit hER-mediated transcription, implicated in breast cancer progression.

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Section: Discussionsupporting

confidence: 89%

Section: Resultsmentioning

confidence: 98%