Data/hora: 24/05/2024 20:40:04

Biblioteca(s): 	Embrapa Agricultura Digital.	
Data corrente: 	19/08/2013	
Data da última atualização: 	22/05/2024	
Autoria: 	BOARETO, M.; YAMAGISHI, M. E. B.; CATICHA, N.; LEITE, V. B. P.	
Afiliação: 	MARCELO BOARETO, USP; MICHEL EDUARDO BELEZA YAMAGISHI, CNPTIA; NESTOR CATICHA, USP; VITOR B. P. LEITE, Unesp.	
Título: 	Relationship between global structural parameters and Enzyme Commission hierarchy: implications for function prediction.	
Ano de publicação: 	2012	
Fonte/Imprenta: 	Computational Biology and Chemistry, Oxford, v. 40, p. 15-19, 2012.	
DOI: 	https://doi.org/10.1016/j.compbiolchem.2012.06.003	
Idioma: 	Inglês	
Conteúdo: 	In protein databases there is a substantial number of proteins structurally determined but without function annotation. Understanding the relationship between function and structure can be useful to predict function on a large scale. We have analyzed the similarities in global physicochemical parameters for a set of enzymes which were classified according to the four Enzyme Commission (EC) hierarchical levels. Using relevance theory we introduced a distance between proteins in the space of physicochemical characteristics. This was done by minimizing a cost function of the metric tensor built to reflect the EC classification system. Using an unsupervised clustering method on a set of 1025 enzymes, we obtained no relevant clustering formation compatible with EC classification. The distance distributions between enzymes from the same EC group and from different EC groups were compared by histograms. Such analysis was also performed using sequence alignment similarity as a distance. Our results suggest that global structure parameters are not sufficient to segregate enzymes according to EC hierarchy. This indicates that features essential for function are rather local than global. Consequently, methods for predicting function based on global attributes should not obtain high accuracy in main EC classes prediction without relying on similarities between enzymes from training and validation datasets. Furthermore, these results are consistent with a substantial number of studies suggesting that function evolves fundamentally by recruitment, i.e., a same protein motif or fold can be used to perform different enzymatic functions and a few specific amino acids (AAs) are actually responsible for enzyme activity. These essential amino acids should belong to active sites and an effective method for predicting function should be able to recognize them.	
Palavras-Chave: 	Bioinformática; Enzyme structure; Estrutura de enzimas; Function prediction; Parâmetros físico-químicos; Physicochemical parameters; Previsão de função.	
Thesaurus Nal: 	Bioinformatics.	
Categoria do assunto: 	X Pesquisa, Tecnologia e Engenharia	
Registro original: 	Embrapa Agricultura Digital (CNPTIA)	
Exemplares: 	CNPTIA - (17517-1) - UPC - AP - DD -  -  -  - DIS