| Structural highlights
Function
PPAF2_HOLDI Binds and activates processed prophenoloxidases PPO1 and PPO2 and thus is involved in the activation of the prophenoloxidase cascade probably following the recognition of pathogen-derived products.[1] [2] [3] [4] [5]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Clip-domain serine proteases (SPs) are the essential components of extracellular signaling cascades in various biological processes, especially in embryonic development and the innate immune responses of invertebrates. They consist of a chymotrypsin-like SP domain and one or two clip domains at the N-terminus. Prophenoloxidase-activating factor (PPAF)-II, which belongs to the noncatalytic clip-domain SP family, is indispensable for the generation of the active phenoloxidase leading to melanization, a major defense mechanism of insects. Here, the crystal structure of PPAF-II reveals that the clip domain adopts a novel fold containing a central cleft, which is distinct from the structures of defensins with a similar arrangement of cysteine residues. Ensuing studies demonstrated that PPAF-II forms a homo-oligomer upon cleavage by the upstream protease and that the clip domain of PPAF-II functions as a module for binding phenoloxidase through the central cleft, while the clip domain of a catalytically active easter-type SP plays an essential role in the rapid activation of its protease domain.
Crystal structure of a clip-domain serine protease and functional roles of the clip domains.,Piao S, Song YL, Kim JH, Park SY, Park JW, Lee BL, Oh BH, Ha NC EMBO J. 2005 Dec 21;24(24):4404-14. Epub 2005 Dec 15. PMID:16362048[6]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kwon TH, Kim MS, Choi HW, Joo CH, Cho MY, Lee BL. A masquerade-like serine proteinase homologue is necessary for phenoloxidase activity in the coleopteran insect, Holotrichia diomphalia larvae. Eur J Biochem. 2000 Oct;267(20):6188-96. PMID:11012672 doi:10.1046/j.1432-1327.2000.01695.x
- ↑ Kim MS, Baek MJ, Lee MH, Park JW, Lee SY, Soderhall K, Lee BL. A new easter-type serine protease cleaves a masquerade-like protein during prophenoloxidase activation in Holotrichia diomphalia larvae. J Biol Chem. 2002 Oct 18;277(42):39999-40004. PMID:12185078 doi:10.1074/jbc.M205508200
- ↑ Piao S, Song YL, Kim JH, Park SY, Park JW, Lee BL, Oh BH, Ha NC. Crystal structure of a clip-domain serine protease and functional roles of the clip domains. EMBO J. 2005 Dec 21;24(24):4404-14. Epub 2005 Dec 15. PMID:16362048
- ↑ Lee SY, Kwon TH, Hyun JH, Choi JS, Kawabata SI, Iwanaga S, Lee BL. In vitro activation of pro-phenol-oxidase by two kinds of pro-phenol-oxidase-activating factors isolated from hemolymph of coleopteran, Holotrichia diomphalia larvae. Eur J Biochem. 1998 May 15;254(1):50-7. PMID:9652393 doi:10.1046/j.1432-1327.1998.2540050.x
- ↑ Kim MS, Baek MJ, Lee MH, Park JW, Lee SY, Soderhall K, Lee BL. A new easter-type serine protease cleaves a masquerade-like protein during prophenoloxidase activation in Holotrichia diomphalia larvae. J Biol Chem. 2002 Oct 18;277(42):39999-40004. PMID:12185078 doi:10.1074/jbc.M205508200
- ↑ Piao S, Song YL, Kim JH, Park SY, Park JW, Lee BL, Oh BH, Ha NC. Crystal structure of a clip-domain serine protease and functional roles of the clip domains. EMBO J. 2005 Dec 21;24(24):4404-14. Epub 2005 Dec 15. PMID:16362048
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