A unique insertion of low complexity amino acid sequence underlies protein-protein interaction in human malaria parasite orotate phosphoribosyltransferase and orotidine 5'-monophosphate decarboxylase  

作　　者：Waranya Imprasittichai Sittiruk Roytrakul Sudaratana R.Krungkrai Jcrapan Krungkrai 

机构地区：[1]Department of Biochemistry.Faculty of Medicine.Chulalongkorn University [2]National Center for Genetic Engineering and Biotechnology [3]Unit of Biochemistry.Department of Medical Science.Faculty of Science,Rangsit University

出　　处：《Asian Pacific Journal of Tropical Medicine》2014年第3期184-192,共9页亚太热带医药杂志（英文版）

基　　金：supported in part by Faculty of Graduate School(to W.L);Faculty of Medicine(contract no. RAH/54(1) to J.K.),Chulalongkorn University

摘　　要：Objective:To investigate the multienzyine complex formation of human malaria parasite Plasmodium falciparum[P.falciparum)orotate phosphoribosyltransferase(OPRT)and orotidine5'-monophosphate decarboxylase(OMPDC),the fifth and sixth enzyme of the de novo pyrimidine biosynthetic palhway.Previously,we have clearly established that the two enzymes in the malaria parasite exist physically as a heterotetrameric(OPRT)_2(OMPDG)_2 complex containing two subunits each of OPRT and OMPDC.and that the complex have catalytic kinetic advantages over the monofunetional enzyme.Methods:Both enzymes were cloned and expressed as recombinant proteins.The protein-protein interaction in the enzyme complex was identified using bifunctionul chemical cross-linker,liquid chromatography-mass spectrometric analysis and homology modeling,Results:The unique insertions of low complexity region at the a 2 and a 5 helices of the parasite OMPDC,characterized by single amino acid repeat sequence which was not found in homologous proteins from other organisms,was located on the OPRT-OMPDC interface.The structural models for the protein-prolein interaction of the helerotetrameric(OPRT)_2(OMPDC)_2multienzyme complex were proposed.Conclusions:Based on the proteomic data and structural modeling,it is surmised that the human malaria parasite low complexity region is responsible for the OPRT-OMPDC interaction.The structural complex of the parasite enzymes,thus,represents an efficient functional kinetic advantage,which in line with co-localization principles of evolutional origin,and allosteric control in protein-protein-interactions.Objective:To investigate the multienzyine complex formation of human malaria parasite Plasmodium falciparum[P.falciparum)orotate phosphoribosyltransferase（OPRT）and orotidine5’-monophosphate decarboxylase（OMPDC）,the fifth and sixth enzyme of the de novo pyrimidine biosynthetic palhway.Previously,we have clearly established that the two enzymes in the malaria parasite exist physically as a heterotetrameric（OPRT）2（OMPDG）2 complex containing two subunits each of OPRT and OMPDC.and that the complex have catalytic kinetic advantages over the monofunetional enzyme.Methods:Both enzymes were cloned and expressed as recombinant proteins.The protein-protein interaction in the enzyme complex was identified using bifunctionul chemical cross-linker,liquid chromatography-mass spectrometric analysis and homology modeling,Results:The unique insertions of low complexity region at the a 2 and a 5 helices of the parasite OMPDC,characterized by single amino acid repeat sequence which was not found in homologous proteins from other organisms,was located on the OPRT-OMPDC interface.The structural models for the protein-prolein interaction of the helerotetrameric（OPRT）2（OMPDC）2multienzyme complex were proposed.Conclusions:Based on the proteomic data and structural modeling,it is surmised that the human malaria parasite low complexity region is responsible for the OPRT-OMPDC interaction.The structural complex of the parasite enzymes,thus,represents an efficient functional kinetic advantage,which in line with co-localization principles of evolutional origin,and allosteric control in protein-protein-interactions.

关 键 词：Malaria PLASMODIUM FALCIPARUM PYRIMIDINE biosynthesis Orotate PHOSPHORIBOSYLTRANSFERASE Orotidine 5’-monophosphate DECARBOXYLASE Multienzyme complex Proteomics 

分 类 号：R382[医药卫生—医学寄生虫学]