| Structural highlights
7oy2 is a 3 chain structure with sequence from Escherichia coli K-12. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | , , , , , |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
APPB_ECOLI A terminal oxidase that catalyzes quinol-dependent, Na(+)-independent oxygen uptake. Prefers menadiol over other quinols although ubiquinol was not tested (PubMed:8626304). Generates a proton motive force using protons and electrons from opposite sides of the membrane to generate H(2)O, transferring 1 proton/electron.[1] [2] [3] [4]
Publication Abstract from PubMed
The treatment of infectious diseases caused by multidrug-resistant pathogens is a major clinical challenge of the 21st century. The membrane-embedded respiratory cytochrome bd-type oxygen reductase is a critical survival factor utilized by pathogenic bacteria during infection, proliferation and the transition from acute to chronic states. Escherichia coli encodes for two cytochrome bd isoforms that are both involved in respiration under oxygen limited conditions. Mechanistic and structural differences between cydABX (Ecbd-I) and appCBX (Ecbd-II) operon encoded cytochrome bd variants have remained elusive in the past. Here, we demonstrate that cytochrome bd-II catalyzes oxidation of benzoquinols while possessing additional specificity for naphthoquinones. Our data show that although menaquinol-1 (MK1) is not able to directly transfer electrons onto cytochrome bd-II from E. coli, it has a stimulatory effect on its oxygen reduction rate in the presence of ubiquinol-1. We further determined cryo-EM structures of cytochrome bd-II to high resolution of 2.1 A. Our structural insights confirm that the general architecture and substrate accessible pathways are conserved between the two bd oxidase isoforms, but two notable differences are apparent upon inspection: (i) Ecbd-II does not contain a CydH-like subunit, thereby exposing heme b(595) to the membrane environment and (ii) the AppB subunit harbors a structural demethylmenaquinone-8 molecule instead of ubiquinone-8 as found in CydB of Ecbd-I Our work completes the structural landscape of terminal respiratory oxygen reductases of E. coli and suggests that structural and functional properties of the respective oxidases are linked to quinol-pool dependent metabolic adaptations in E. coli.
Mechanistic and structural diversity between cytochrome bd isoforms of Escherichia coli.,Grund TN, Radloff M, Wu D, Goojani HG, Witte LF, Josting W, Buschmann S, Muller H, Elamri I, Welsch S, Schwalbe H, Michel H, Bald D, Safarian S Proc Natl Acad Sci U S A. 2021 Dec 14;118(50):e2114013118. doi: , 10.1073/pnas.2114013118. PMID:34873041[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bekker M, de Vries S, Ter Beek A, Hellingwerf KJ, de Mattos MJ. Respiration of Escherichia coli can be fully uncoupled via the nonelectrogenic terminal cytochrome bd-II oxidase. J Bacteriol. 2009 Sep;191(17):5510-7. doi: 10.1128/JB.00562-09. Epub 2009 Jun 19. PMID:19542282 doi:http://dx.doi.org/10.1128/JB.00562-09
- ↑ Borisov VB, Murali R, Verkhovskaya ML, Bloch DA, Han H, Gennis RB, Verkhovsky MI. Aerobic respiratory chain of Escherichia coli is not allowed to work in fully uncoupled mode. Proc Natl Acad Sci U S A. 2011 Oct 18;108(42):17320-4. doi:, 10.1073/pnas.1108217108. Epub 2011 Oct 10. PMID:21987791 doi:http://dx.doi.org/10.1073/pnas.1108217108
- ↑ Sharma P, Hellingwerf KJ, de Mattos MJ, Bekker M. Uncoupling of substrate-level phosphorylation in Escherichia coli during glucose-limited growth. Appl Environ Microbiol. 2012 Oct;78(19):6908-13. doi: 10.1128/AEM.01507-12. Epub , 2012 Jul 27. PMID:22843529 doi:http://dx.doi.org/10.1128/AEM.01507-12
- ↑ Sturr MG, Krulwich TA, Hicks DB. Purification of a cytochrome bd terminal oxidase encoded by the Escherichia coli app locus from a delta cyo delta cyd strain complemented by genes from Bacillus firmus OF4. J Bacteriol. 1996 Mar;178(6):1742-9. PMID:8626304
- ↑ Grund TN, Radloff M, Wu D, Goojani HG, Witte LF, Josting W, Buschmann S, Muller H, Elamri I, Welsch S, Schwalbe H, Michel H, Bald D, Safarian S. Mechanistic and structural diversity between cytochrome bd isoforms of Escherichia coli. Proc Natl Acad Sci U S A. 2021 Dec 14;118(50):e2114013118. doi: , 10.1073/pnas.2114013118. PMID:34873041 doi:http://dx.doi.org/10.1073/pnas.2114013118
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