Limits...
Protein disulfide bond generation in Escherichia coli DsbB-DsbA.

Inaba K - J Synchrotron Radiat (2008)

Bottom Line: Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli.The crystal structure of the DsbB-DsbA-ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA.The structural basis for prevention of the crosstalk between the DsbA-DsbB oxidative and the DsbC-DsbD reductive pathways has also been proposed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan. inaba-k@bioreg.kyushu-u.ac.jp

ABSTRACT
Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli. The crystal structure of the DsbB-DsbA-ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA. The structural basis for prevention of the crosstalk between the DsbA-DsbB oxidative and the DsbC-DsbD reductive pathways has also been proposed.

Show MeSH

Related in: MedlinePlus

(a) UQ-binding site on DsbB. (b) Difference Fourier map constructed from UQ-bound and UQ-free forms of crystals. (c) Chemical scheme for disulfide bond generation cooperated by DsbB and UQ.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2394806&req=5

fig3: (a) UQ-binding site on DsbB. (b) Difference Fourier map constructed from UQ-bound and UQ-free forms of crystals. (c) Chemical scheme for disulfide bond generation cooperated by DsbB and UQ.

Mentions: The UQ-binding site on DsbB has not unequivocally been determined in the past. Our crystallographic data indicate the presence of a prominent area of electron density near the N-terminal end of TM2, whose dimension fits that of the quinone ring (Fig. 3 ▶ a). Although the electron density of the isoprenoid chain of UQ was invisible, the disc-like electron density could represent the head group of endogenous UQ8. The difference Fourier map calculated from the UQ8-bound and the UQ-free crystals demonstrates a strong UQ-specific peak at the position that coincides with the electron-dense area addressed above (Fig. 3 ▶ b). The quinone-binding site we specified here is consistent with the formation of the Cys44-UQ charge-transfer complex and its enhancement by Arg48 (Inaba et al., 2004 ▶; Inaba, Takahashi et al., 2006 ▶), a residue of an implicated quinone-binding role. The area of DsbB having UQ aligned with Cys41, Cys44 and Arg48 can be regarded as the reaction center, where disulfide bonds are generated de novo along the chemical scheme shown in Fig. 3 ▶(c) (Inaba, Takahashi et al., 2006 ▶).


Protein disulfide bond generation in Escherichia coli DsbB-DsbA.

Inaba K - J Synchrotron Radiat (2008)

(a) UQ-binding site on DsbB. (b) Difference Fourier map constructed from UQ-bound and UQ-free forms of crystals. (c) Chemical scheme for disulfide bond generation cooperated by DsbB and UQ.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2394806&req=5

fig3: (a) UQ-binding site on DsbB. (b) Difference Fourier map constructed from UQ-bound and UQ-free forms of crystals. (c) Chemical scheme for disulfide bond generation cooperated by DsbB and UQ.
Mentions: The UQ-binding site on DsbB has not unequivocally been determined in the past. Our crystallographic data indicate the presence of a prominent area of electron density near the N-terminal end of TM2, whose dimension fits that of the quinone ring (Fig. 3 ▶ a). Although the electron density of the isoprenoid chain of UQ was invisible, the disc-like electron density could represent the head group of endogenous UQ8. The difference Fourier map calculated from the UQ8-bound and the UQ-free crystals demonstrates a strong UQ-specific peak at the position that coincides with the electron-dense area addressed above (Fig. 3 ▶ b). The quinone-binding site we specified here is consistent with the formation of the Cys44-UQ charge-transfer complex and its enhancement by Arg48 (Inaba et al., 2004 ▶; Inaba, Takahashi et al., 2006 ▶), a residue of an implicated quinone-binding role. The area of DsbB having UQ aligned with Cys41, Cys44 and Arg48 can be regarded as the reaction center, where disulfide bonds are generated de novo along the chemical scheme shown in Fig. 3 ▶(c) (Inaba, Takahashi et al., 2006 ▶).

Bottom Line: Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli.The crystal structure of the DsbB-DsbA-ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA.The structural basis for prevention of the crosstalk between the DsbA-DsbB oxidative and the DsbC-DsbD reductive pathways has also been proposed.

View Article: PubMed Central - HTML - PubMed

Affiliation: Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan. inaba-k@bioreg.kyushu-u.ac.jp

ABSTRACT
Protein disulfide bond formation is catalyzed by a series of Dsb enzymes present in the periplasm of Escherichia coli. The crystal structure of the DsbB-DsbA-ubiquinone ternary complex provided important insights into mechanisms of the de novo disulfide bond generation cooperated by DsbB and ubiquinone and of the disulfide bond shuttle from DsbB to DsbA. The structural basis for prevention of the crosstalk between the DsbA-DsbB oxidative and the DsbC-DsbD reductive pathways has also been proposed.

Show MeSH
Related in: MedlinePlus