Evolution of the histones: free play with exon shuffling

In higher eukaryotes, the nuclear DNA is organized for transcription, replication and mitosis in competent chromatin and chromosomes. The basic unit of chromatin is the nucleosome. This entity is formed by 168 base pairs of DNA wound around an octamer of histones, this octamer of histones consist of...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autor principal:	TORO,G. CECILIA
Lenguaje:	English
Publicado:	Sociedad de Biología de Chile 2001
Materias:	histones evolution
Acceso en línea:	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000020
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:scielo:S0716-078X2001000000020
record_format	dspace
spelling	oai:scielo:S0716-078X20010000000202001-06-27Evolution of the histones: free play with exon shufflingTORO,G. CECILIA histones evolution In higher eukaryotes, the nuclear DNA is organized for transcription, replication and mitosis in competent chromatin and chromosomes. The basic unit of chromatin is the nucleosome. This entity is formed by 168 base pairs of DNA wound around an octamer of histones, this octamer of histones consist of two copies of H2A, H2B, H3 and H4. The DNA is sealed in its input and output point by a histone linker: histone H1. Histones were supposed to be very conserved proteins. However, during the past few years it was found that these proteins present a high degree of divergency in several lower eukaryotes. In Trypanosoma, it was found that histones H3 and H4, which are at the center of the nucleosomal organization, showed more than 30 % of divergency, while histone H1 corresponded to only one of the three peptide domains present in higher eukaryotes. These features of Trypanosoma histones may explain, at least in part, the unability of chromatin to condense into chromosomes during the cell division in these parasites. Evolution of histones was usually considered as peculiar, with several proposals which are difficult to reconcile with experimental data. In the present work, it is proposed that histones followed the same evolutionary route as many other proteins. Considering that exons code for structural and functional domains in proteins and that, at the origin of eukaryotes, the histones, as other proteins, could be formed by "units" (mecano theory), it was expected that these units or domains eventually would be found in living organisms exhibiting primitive features. Furthermore, those units could work independently. Our results on the structure of Trypanosoma cruzi histone genes and proteins as well as the analysis of other histones from different species fit with this proposalinfo:eu-repo/semantics/openAccessSociedad de Biología de ChileRevista chilena de historia natural v.74 n.1 20012001-03-01text/htmlhttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000020en10.4067/S0716-078X2001000000020
institution	Scielo Chile
collection	Scielo Chile
language	English
topic	histones evolution
spellingShingle	histones evolution TORO,G. CECILIA Evolution of the histones: free play with exon shuffling
description	In higher eukaryotes, the nuclear DNA is organized for transcription, replication and mitosis in competent chromatin and chromosomes. The basic unit of chromatin is the nucleosome. This entity is formed by 168 base pairs of DNA wound around an octamer of histones, this octamer of histones consist of two copies of H2A, H2B, H3 and H4. The DNA is sealed in its input and output point by a histone linker: histone H1. Histones were supposed to be very conserved proteins. However, during the past few years it was found that these proteins present a high degree of divergency in several lower eukaryotes. In Trypanosoma, it was found that histones H3 and H4, which are at the center of the nucleosomal organization, showed more than 30 % of divergency, while histone H1 corresponded to only one of the three peptide domains present in higher eukaryotes. These features of Trypanosoma histones may explain, at least in part, the unability of chromatin to condense into chromosomes during the cell division in these parasites. Evolution of histones was usually considered as peculiar, with several proposals which are difficult to reconcile with experimental data. In the present work, it is proposed that histones followed the same evolutionary route as many other proteins. Considering that exons code for structural and functional domains in proteins and that, at the origin of eukaryotes, the histones, as other proteins, could be formed by "units" (mecano theory), it was expected that these units or domains eventually would be found in living organisms exhibiting primitive features. Furthermore, those units could work independently. Our results on the structure of Trypanosoma cruzi histone genes and proteins as well as the analysis of other histones from different species fit with this proposal
author	TORO,G. CECILIA
author_facet	TORO,G. CECILIA
author_sort	TORO,G. CECILIA
title	Evolution of the histones: free play with exon shuffling
title_short	Evolution of the histones: free play with exon shuffling
title_full	Evolution of the histones: free play with exon shuffling
title_fullStr	Evolution of the histones: free play with exon shuffling
title_full_unstemmed	Evolution of the histones: free play with exon shuffling
title_sort	evolution of the histones: free play with exon shuffling
publisher	Sociedad de Biología de Chile
publishDate	2001
url	http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000020
work_keys_str_mv	AT torogcecilia evolutionofthehistonesfreeplaywithexonshuffling
_version_	1718439502044725248

Evolution of the histones: free play with exon shuffling

Ejemplares similares