| Structural highlights
Function
PP62_ASFB7 Essential for the correct assembly and maturation of the core of the virion.[1] Component of the core shell (PubMed:30185597). Binds to phosphatidylserine, which may enable the core shell binding with the inner membrane (PubMed:32519301).[2] [3] Component of the core shell (PubMed:30185597). Binds to phosphatidylserine and DNA, which may link the core shell to the inner membrane and to the viral nucleoid (PubMed:32451720).[4] [5] Component of the core shell.[6] BFRB_PSEAE The major iron-storage protein, part of the heterooligomeric bacterioferritin (BFR) complex. The ferroxidase center binds Fe(2+), oxidizes it using dioxygen to Fe(3+), and participates in the subsequent Fe(3+) oxide mineral core formation within the central cavity of the BFR protein shell. Can store up to 600 iron atoms per bacterioferritin protein molecule (PubMed:19575528, PubMed:20067302, PubMed:25640193, PubMed:26368531). In iron-sufficient conditions (10 uM Fe(2+)) iron accumulates in BFR until about 12 hours, when it starts to deplete; stored iron is no longer detectable by 24 hours growth, iron is mobilized from the BFR as levels drop in the growth media (PubMed:28318006). Iron release from the BFR requires ferredoxin NADP reductase (FPR) and bacterioferritin-associated ferredoxin (Bfd) (PubMed:19575528, PubMed:22812654, PubMed:26368531). Reduction of the BfrB heme group occurs in the presence of Bfd, strongly suggesting that the BfrB-Bfd complex allows heme to mediate electron transfer from FPR to the Fe(3+) iron core in the BFR shell prior to its release as Fe(2+) (PubMed:19575528, PubMed:22812654, PubMed:26368531).[7] [8] [9] [10] [11] [12]
Publication Abstract from PubMed
The iron storage protein bacterioferritin (BfrB) is central to bacterial iron homeostasis. The mobilization of iron from BfrB, which requires binding by a cognate ferredoxin (Bfd), is essential to the regulation of cytosolic iron levels in P. aeruginosa. This paper describes the structure-guided development of small molecule inhibitors of the BfrB-Bfd protein-protein interaction. The process was initiated by screening a fragment library and followed by obtaining the structure of a fragment hit bound to BfrB. The structural insights were used to develop a series of 4-(benzylamino)- and 4-((3-phenylpropyl)amino)-isoindoline-1,3-dione analogs that selectively bind BfrB at the Bfd binding site. Challenging P. aeruginosa cells with the 4-substituted isoindoline analogs revealed a dose-dependent growth phenotype. Further investigation determined that the analogs elicit a pyoverdin hyperproduction phenotype that is consistent with blockade of the BfrB-Bfd interaction and ensuing irreversible accumulation of iron in BfrB, with concomitant depletion of iron in the cytosol. The irreversible accumulation of iron in BfrB prompted by the 4-substituted isoindoline analogs was confirmed by visualization of BfrB-iron in P. aeruginosa cell lysates separated on native PAGE gels and stained for iron with Ferene S. Challenging P. aeruginosa cultures with a combination of commercial fluoroquinolone and our isoindoline analogs results in significantly lower cell survival relative to treatment with either antibiotic or analog alone. Collectively, these findings furnish proof of concept for the usefulness of small molecule probes designed to dysregulate bacterial iron homeostasis by targeting a protein-protein interaction pivotal for iron storage in the bacterial cell.
Small Molecule Inhibitors of the BfrB-Bfd Interaction Decrease Pseudomonas aeruginosa Fitness and Potentiate Fluoroquinolone Activity.,Punchi Hewage AND, Yao H, Nammalwar B, Gnanasekaran KK, Lovell S, Bunce RA, Eshelman K, Phaniraj SM, Lee MM, Peterson BR, Battaile KP, Reitz AB, Rivera M J Am Chem Soc. 2019 May 9. doi: 10.1021/jacs.9b00394. PMID:31038945[13]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Suarez C, Salas ML, Rodriguez JM. African swine fever virus polyprotein pp62 is essential for viral core development. J Virol. 2010 Jan;84(1):176-87. doi: 10.1128/JVI.01858-09. PMID:19846532 doi:https://dx.doi.org/10.1128/JVI.01858-09
- ↑ Alejo A, Matamoros T, Guerra M, Andres G. A Proteomic Atlas of the African Swine Fever Virus Particle. J Virol. 2018 Nov 12;92(23). pii: JVI.01293-18. doi: 10.1128/JVI.01293-18. Print , 2018 Dec 1. PMID:30185597 doi:https://dx.doi.org/10.1128/JVI.01293-18
- ↑ Li G, Fu D, Zhang G, Zhao D, Li M, Geng X, Sun D, Wang Y, Chen C, Jiao P, Cao L, Guo Y, Rao Z. Crystal structure of the African swine fever virus structural protein p35 reveals its role for core shell assembly. Protein Cell. 2020 Aug;11(8):600-605. doi: 10.1007/s13238-020-00730-w. PMID:32519301 doi:https://dx.doi.org/10.1007/s13238-020-00730-w
- ↑ Alejo A, Matamoros T, Guerra M, Andres G. A Proteomic Atlas of the African Swine Fever Virus Particle. J Virol. 2018 Nov 12;92(23). pii: JVI.01293-18. doi: 10.1128/JVI.01293-18. Print , 2018 Dec 1. PMID:30185597 doi:https://dx.doi.org/10.1128/JVI.01293-18
- ↑ Fu D, Zhao D, Zhang W, Zhang G, Li M, Zhang Z, Wang Y, Sun D, Jiao P, Chen C, Guo Y, Rao Z. Structure of African swine fever virus p15 reveals its dual role for membrane-association and DNA binding. Protein Cell. 2020 Aug;11(8):606-612. doi: 10.1007/s13238-020-00731-9. PMID:32451720 doi:https://dx.doi.org/10.1007/s13238-020-00731-9
- ↑ Alejo A, Matamoros T, Guerra M, Andres G. A Proteomic Atlas of the African Swine Fever Virus Particle. J Virol. 2018 Nov 12;92(23). pii: JVI.01293-18. doi: 10.1128/JVI.01293-18. Print , 2018 Dec 1. PMID:30185597 doi:https://dx.doi.org/10.1128/JVI.01293-18
- ↑ Weeratunga SK, Gee CE, Lovell S, Zeng Y, Woodin CL, Rivera M. Binding of Pseudomonas aeruginosa apobacterioferritin-associated ferredoxin to bacterioferritin B promotes heme mediation of electron delivery and mobilization of core mineral iron. Biochemistry. 2009 Aug 11;48(31):7420-31. PMID:19575528 doi:10.1021/bi900561a
- ↑ Weeratunga SK, Lovell S, Yao H, Battaile KP, Fischer CJ, Gee CE, Rivera M. Structural Studies of Bacterioferritin B from Pseudomonas aeruginosa Suggest a Gating Mechanism for Iron Uptake via the Ferroxidase Center . Biochemistry. 2010 Jan 21. PMID:20067302 doi:10.1021/bi9015204
- ↑ Yao H, Wang Y, Lovell SW, Kumar R, Ruvinsky AM, Battaile KP, Vakser IA, Rivera M. The structure of the BfrB-Bfd complex reveals protein-protein interactions enabling iron release from bacterioferritin. J Am Chem Soc. 2012 Jul 19. PMID:22812654 doi:10.1021/ja305180n
- ↑ Yao H, Rui H, Kumar R, Eshelman K, Lovell S, Battaile KP, Im W, Rivera M. Concerted Motions Networking Pores and Distant Ferroxidase Centers Enable Bacterioferritin Function and Iron Traffic. Biochemistry. 2015 Jan 31. PMID:25640193 doi:https://dx.doi.org/10.1021/bi501255r
- ↑ Wang Y, Yao H, Cheng Y, Lovell SW, Battaile KP, Middaugh CR, Rivera M. Characterization of the Bacterioferritin/Bacterioferritin Associated Ferredoxin (BfrB:Bfd) Protein-Protein Interaction in Solution and Determination of Binding Energy Hot Spots. Biochemistry. 2015 Sep 28. PMID:26368531 doi:https://dx.doi.org/10.1021/acs.biochem.5b00937
- ↑ Eshelman K, Yao H, Punchi Hewage AND, Deay JJ, Chandler JR, Rivera M. Inhibiting the BfrB:Bfd interaction in Pseudomonas aeruginosa causes irreversible iron accumulation in bacterioferritin and iron deficiency in the bacterial cytosol. Metallomics. 2017 Jun 21;9(6):646-659. PMID:28318006 doi:10.1039/c7mt00042a
- ↑ Punchi Hewage AND, Yao H, Nammalwar B, Gnanasekaran KK, Lovell S, Bunce RA, Eshelman K, Phaniraj SM, Lee MM, Peterson BR, Battaile KP, Reitz AB, Rivera M. Small Molecule Inhibitors of the BfrB-Bfd Interaction Decrease Pseudomonas aeruginosa Fitness and Potentiate Fluoroquinolone Activity. J Am Chem Soc. 2019 May 9. doi: 10.1021/jacs.9b00394. PMID:31038945 doi:https://dx.doi.org/10.1021/jacs.9b00394
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