Characterization of monomeric DNA-binding protein Histone H1 in Leishmania braziliensis. Carmelo E, González G, Cruz T, Osuna A, Hernández M, Valladares B. Parasitology. 2011 Aug;138(9):1093-101. doi: 10.1017/S0031182011000898. Epub 2011 Jul 18. PMID: 21767437

Abstract

Histone H1 in Leishmania presents relevant differences compared to higher eukaryote counterparts, such as the lack of a DNA-binding central globular domain. Despite that, it is apparently fully functional since its differential expression levels have been related to changes in chromatin condensation and infectivity, among other features. The localization and the aggregation state of L. braziliensis H1 has been determined by immunolocalization, mass spectrometry, cross-linking and electrophoretic mobility shift assays. Analysis of H1 sequences from the Leishmania Genome Database revealed that our protein is included in a very divergent group of histones H1 thatis presentonly in L. braziliensis. An antibody raised against recombinantL.braziliensis H1recognizedspecifically thatproteinbyimmunoblotinL.braziliensisextracts,butnotinother Leishmania species, a consequence of the sequence divergences observed among Leishmania species. Mass spectrometry analysis and in vitro DNA-binding experiments have also proven that L. braziliensis H1 is monomeric in solution, but oligomerizes upon binding to DNA. Finally, despite the lack of a globular domain, L. braziliensis H1 is able to form complexes with DNA in vitro, with higher affinity for supercoiled compared to linear DNA.