Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-11T20:43:50Z No. of bitstreams: 1 RicardoVictorMachadoDeAlmeida_DISSERT.pdf: 6652554 bytes, checksum: 6cdb4c4527db5842187ddfa525762e72 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-11T20:54:52Z (GMT) No. of bitstreams: 1 RicardoVictorMachadoDeAlmeida_DISSERT.pdf: 6652554 bytes, checksum: 6cdb4c4527db5842187ddfa525762e72 (MD5) / Made available in DSpace on 2016-01-11T20:54:52Z (GMT). No. of bitstreams: 1 RicardoVictorMachadoDeAlmeida_DISSERT.pdf: 6652554 bytes, checksum: 6cdb4c4527db5842187ddfa525762e72 (MD5) Previous issue date: 2014-08-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / O metabolismo vegetal ? composto por uma complexa rede de eventos f?sicos e qu?micos que resultam na fotoss?ntese, respira??o, e na s?ntese e degrada??o de compostos org?nicos. Isto s? ? poss?vel gra?as aos diferentes tipos de respostas a in?meras varia??es ambientais que um vegetal pode estar sujeito, adquiridas ao longo da evolu??o, levando tamb?m a conquistas de novos ambientes. O ciclo do glioxilato ? uma via metab?lica localizada nos glioxissomos de plantas, que possui papel ?nico no estabelecimento das pl?ntulas. Considerado como uma varia??o do ciclo do ?cido c?trico esta via utiliza uma mol?cula de acetil-Coenzima A, oriunda da beta-oxida??o de lip?dios para sintetizar compostos que s?o utilizados na s?ntese de carboidratos. As enzimas Malato sintase (MLS) e Isocitrato liase (ICL) s?o exclusivas deste ciclo e essenciais na regula??o da bioss?ntese de carboidratos. Devido ? aus?ncia das etapas de descarboxila??o, como fatores limitantes da velocidade, estudos mais detalhados da filogenia e evolu??o molecular dessas prote?nas permite o esclarecimento dos efeitos da presen?a desta rota nos processos evolutivos envolvidos em esp?cies vegetais. Portanto, o objetivo deste trabalho foi estudar a rela??o entre a evolu??o molecular das enzimas Isocitrato liase e Malato sintase e sua filogenia, nas plantas verdes (Viridiplantae). Para isso, foram utilizadas sequ?ncias de amino?cidos e nucleot?deos dos genes, a partir de reposit?rios online como o Genbank e Uniprot. As sequ?ncias foram alinhadas e, em seguida, submetidos ? an?lise estat?stica dos modelos de melhor ajuste de substitui??o. A filogenia foi reconstru?da por m?todos de dist?ncia (Neighbor-joining) e m?todos discretos (M?xima Verossimilhan?a, M?xima Parcim?nia e An?lise Bayesiana). O reconhecimento de padr?es estruturais na evolu??o das enzimas foi feito por predi??o e modelagem por homologia das estruturas das sequ?ncias das prote?nas obtidas. Com base nas an?lises comparativas entre modelos in silico, das enzimas, e partir dos resultados de infer?ncia filogen?tica, ambas as enzimas apresentam um padr?o de conserva??o relativamente elevado em sua estrutura e geram topologias condizentes com dois processos de sele??o e especializa??o dos seus respectivos genes. Deste modo, confirmando a relev?ncia em se realizar novos estudos para se elucidar o metabolismo vegetal sob uma perspectiva evolutiva das rela??es entre os genes e a express?o de suas enzimas / The plant metabolism consists of a complex network of physical and chemical events resulting in photosynthesis, respiration, synthesis and degradation of organic compounds. This is only possible due to the different kinds of responses to many environmental variations that a plant could be subject through evolution, leading also to conquering new surroundings. The glyoxylate cycle is a metabolic pathway found in glyoxysomes plant, which has unique role in the seedling establishment. Considered as a variation of the citric acid cycle, it uses an acetyl coenzyme A molecule, derived from lipids beta-oxidation to synthesize compounds which are used in carbohydrate synthesis. The Malate synthase (MLS) and Isocitrate lyase (ICL) enzyme of this cycle are unique and essential in regulating the biosynthesis of carbohydrates. Because of the absence of decarboxylation steps as rate-limiting steps, detailed studies of molecular phylogeny and evolution of these proteins enables the elucidation of the effects of this route presence in the evolutionary processes involved in their distribution across the genome from different plant species. Therefore, the aim of this study was to establish a relationship between the molecular evolution of the characteristics of enzymes from the glyoxylate cycle (isocitrate lyase and malate synthase) and their molecular phylogeny, among green plants (Viridiplantae). For this, amino acid and nucleotide sequences were used, from online repositories as UniProt and Genbank. Sequences were aligned and then subjected to an analysis of the best-fit substitution models. The phylogeny was rebuilt by distance methods (neighbor-joining) and discrete methods (maximum likelihood, maximum parsimony and Bayesian analysis). The identification of structural patterns in the evolution of the enzymes was made through homology modeling and structure prediction from protein sequences. Based on comparative analyzes of in silico models and from the results of phylogenetic inferences, both enzymes show significant structure conservation and their topologies in agreement with two processes of selection and specialization of the genes. Thus, confirming the relevance of new studies to elucidate the plant metabolism from an evolutionary perspective