| Structural highlights
Function
PKNB_MYCTU Key component of a signal transduction pathway that regulates cell growth and cell division via phosphorylation of target proteins such as GarA, GlmU, PapA5, PbpA, FhaB (Rv0019c), FhaA (Rv0020c), MviN, PstP, EmbR, Rv1422, Rv1747 and RseA. Shows a strong preference for Thr versus Ser as the phosphoacceptor.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Publication Abstract from PubMed
Forkhead-associated (FHA) domains are modules that bind to phosphothreonine (pThr) residues in signaling cascades. The FHA-containing mycobacterial protein GarA is a central element of a phosphorylation-dependent signaling pathway that redirects metabolic flux in response to amino acid starvation or cell growth requirements. GarA acts as a phosphorylation-dependent ON/OFF molecular switch. In its nonphosphorylated ON state, the GarA FHA domain engages in phosphorylation-independent interactions with various metabolic enzymes that orchestrate nitrogen flow, such as 2-oxoglutarate decarboxylase (KGD). However, phosphorylation at the GarA N-terminal region by the protein kinase PknB or PknG triggers autoinhibition through the intramolecular association of the N-terminal domain with the FHA domain, thus blocking all downstream interactions. To investigate these different FHA binding modes, we solved the crystal structures of the mycobacterial upstream (phosphorylation-dependent) complex PknB-GarA and the downstream (phosphorylation-independent) complex GarA-KGD. Our results show that the phosphorylated activation loop of PknB serves as a docking site to recruit GarA through canonical FHA-pThr interactions. However, the same GarA FHA-binding pocket targets an allosteric site on nonphosphorylated KGD, where a key element of recognition is a phosphomimetic aspartate. Further enzymatic and mutagenesis studies revealed that GarA acted as a dynamic allosteric inhibitor of KGD by preventing crucial motions in KGD that are necessary for catalysis. Our results provide evidence for physiological phosphomimetics, supporting numerous mutagenesis studies using such approaches, and illustrate how evolution can shape a single FHA-binding pocket to specifically interact with multiple phosphorylated and nonphosphorylated protein partners.
Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling.,Wagner T, Andre-Leroux G, Hindie V, Barilone N, Lisa MN, Hoos S, Raynal B, Vulliez-Le Normand B, O'Hare HM, Bellinzoni M, Alzari PM Sci Signal. 2019 May 7;12(580). pii: 12/580/eaav9504. doi:, 10.1126/scisignal.aav9504. PMID:31064884[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kang CM, Abbott DW, Park ST, Dascher CC, Cantley LC, Husson RN. The Mycobacterium tuberculosis serine/threonine kinases PknA and PknB: substrate identification and regulation of cell shape. Genes Dev. 2005 Jul 15;19(14):1692-704. Epub 2005 Jun 28. PMID:15985609 doi:http://dx.doi.org/10.1101/gad.1311105
- ↑ Villarino A, Duran R, Wehenkel A, Fernandez P, England P, Brodin P, Cole ST, Zimny-Arndt U, Jungblut PR, Cervenansky C, Alzari PM. Proteomic identification of M. tuberculosis protein kinase substrates: PknB recruits GarA, a FHA domain-containing protein, through activation loop-mediated interactions. J Mol Biol. 2005 Jul 29;350(5):953-63. PMID:15978616 doi:http://dx.doi.org/10.1016/j.jmb.2005.05.049
- ↑ Grundner C, Gay LM, Alber T. Mycobacterium tuberculosis serine/threonine kinases PknB, PknD, PknE, and PknF phosphorylate multiple FHA domains. Protein Sci. 2005 Jul;14(7):1918-21. PMID:15987910 doi:http://dx.doi.org/10.1110/ps.051413405
- ↑ Sharma K, Gupta M, Krupa A, Srinivasan N, Singh Y. EmbR, a regulatory protein with ATPase activity, is a substrate of multiple serine/threonine kinases and phosphatase in Mycobacterium tuberculosis. FEBS J. 2006 Jun;273(12):2711-21. PMID:16817899 doi:http://dx.doi.org/10.1111/j.1742-4658.2006.05289.x
- ↑ Fernandez P, Saint-Joanis B, Barilone N, Jackson M, Gicquel B, Cole ST, Alzari PM. The Ser/Thr protein kinase PknB is essential for sustaining mycobacterial growth. J Bacteriol. 2006 Nov;188(22):7778-84. Epub 2006 Sep 15. PMID:16980473 doi:http://dx.doi.org/10.1128/JB.00963-06
- ↑ Dasgupta A, Datta P, Kundu M, Basu J. The serine/threonine kinase PknB of Mycobacterium tuberculosis phosphorylates PBPA, a penicillin-binding protein required for cell division. Microbiology. 2006 Feb;152(Pt 2):493-504. PMID:16436437 doi:http://dx.doi.org/152/2/493
- ↑ Gupta M, Sajid A, Arora G, Tandon V, Singh Y. Forkhead-associated domain-containing protein Rv0019c and polyketide-associated protein PapA5, from substrates of serine/threonine protein kinase PknB to interacting proteins of Mycobacterium tuberculosis. J Biol Chem. 2009 Dec 11;284(50):34723-34. Epub 2009 Oct 13. PMID:19826007 doi:http://dx.doi.org/M109.058834
- ↑ Parikh A, Verma SK, Khan S, Prakash B, Nandicoori VK. PknB-mediated phosphorylation of a novel substrate, N-acetylglucosamine-1-phosphate uridyltransferase, modulates its acetyltransferase activity. J Mol Biol. 2009 Feb 20;386(2):451-64. Epub 2008 Dec 24. PMID:19121323 doi:10.1016/j.jmb.2008.12.031
- ↑ Barik S, Sureka K, Mukherjee P, Basu J, Kundu M. RseA, the SigE specific anti-sigma factor of Mycobacterium tuberculosis, is inactivated by phosphorylation-dependent ClpC1P2 proteolysis. Mol Microbiol. 2010 Feb;75(3):592-606. doi: 10.1111/j.1365-2958.2009.07008.x., Epub 2009 Dec 16. PMID:20025669 doi:http://dx.doi.org/10.1111/j.1365-2958.2009.07008.x
- ↑ Sajid A, Arora G, Gupta M, Upadhyay S, Nandicoori VK, Singh Y. Phosphorylation of Mycobacterium tuberculosis Ser/Thr phosphatase by PknA and PknB. PLoS One. 2011 Mar 9;6(3):e17871. doi: 10.1371/journal.pone.0017871. PMID:21423706 doi:http://dx.doi.org/10.1371/journal.pone.0017871
- ↑ Gee CL, Papavinasasundaram KG, Blair SR, Baer CE, Falick AM, King DS, Griffin JE, Venghatakrishnan H, Zukauskas A, Wei JR, Dhiman RK, Crick DC, Rubin EJ, Sassetti CM, Alber T. A phosphorylated pseudokinase complex controls cell wall synthesis in mycobacteria. Sci Signal. 2012 Jan 24;5(208):ra7. PMID:22275220 doi:10.1126/scisignal.2002525
- ↑ Wagner T, Andre-Leroux G, Hindie V, Barilone N, Lisa MN, Hoos S, Raynal B, Vulliez-Le Normand B, O'Hare HM, Bellinzoni M, Alzari PM. Structural insights into the functional versatility of an FHA domain protein in mycobacterial signaling. Sci Signal. 2019 May 7;12(580). pii: 12/580/eaav9504. doi:, 10.1126/scisignal.aav9504. PMID:31064884 doi:http://dx.doi.org/10.1126/scisignal.aav9504
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