Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants

Abstract The second and third steps of the histidine biosynthetic pathway (HBP) in plants are catalyzed by a bifunctional enzyme–HISN2. The enzyme consists of two distinct domains, active respectively as a phosphoribosyl-AMP cyclohydrolase (PRA-CH) and phosphoribosyl-ATP pyrophosphatase (PRA-PH). Th...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Wojciech Witek, Joanna Sliwiak, Milosz Ruszkowski
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/ee8560a2ea2a4cecbc3b6682eea46ba7
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:ee8560a2ea2a4cecbc3b6682eea46ba7
record_format	dspace
spelling	oai:doaj.org-article:ee8560a2ea2a4cecbc3b6682eea46ba72021-12-02T14:42:53ZStructural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants10.1038/s41598-021-88920-22045-2322https://doaj.org/article/ee8560a2ea2a4cecbc3b6682eea46ba72021-05-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-88920-2https://doaj.org/toc/2045-2322Abstract The second and third steps of the histidine biosynthetic pathway (HBP) in plants are catalyzed by a bifunctional enzyme–HISN2. The enzyme consists of two distinct domains, active respectively as a phosphoribosyl-AMP cyclohydrolase (PRA-CH) and phosphoribosyl-ATP pyrophosphatase (PRA-PH). The domains are analogous to single-domain enzymes encoded by bacterial hisI and hisE genes, respectively. The calculated sequence similarity networks between HISN2 analogs from prokaryotes and eukaryotes suggest that the plant enzymes are closest relatives of those in the class of Deltaproteobacteria. In this work, we obtained crystal structures of HISN2 enzyme from Medicago truncatula (MtHISN2) and described its architecture and interactions with AMP. The AMP molecule bound to the PRA-PH domain shows positioning of the N1-phosphoribosyl relevant to catalysis. AMP bound to the PRA-CH domain mimics a part of the substrate, giving insights into the reaction mechanism. The latter interaction also arises as a possible second-tier regulatory mechanism of the HBP flux, as indicated by inhibition assays and isothermal titration calorimetry.Wojciech WitekJoanna SliwiakMilosz RuszkowskiNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-16 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Wojciech Witek Joanna Sliwiak Milosz Ruszkowski Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
description	Abstract The second and third steps of the histidine biosynthetic pathway (HBP) in plants are catalyzed by a bifunctional enzyme–HISN2. The enzyme consists of two distinct domains, active respectively as a phosphoribosyl-AMP cyclohydrolase (PRA-CH) and phosphoribosyl-ATP pyrophosphatase (PRA-PH). The domains are analogous to single-domain enzymes encoded by bacterial hisI and hisE genes, respectively. The calculated sequence similarity networks between HISN2 analogs from prokaryotes and eukaryotes suggest that the plant enzymes are closest relatives of those in the class of Deltaproteobacteria. In this work, we obtained crystal structures of HISN2 enzyme from Medicago truncatula (MtHISN2) and described its architecture and interactions with AMP. The AMP molecule bound to the PRA-PH domain shows positioning of the N1-phosphoribosyl relevant to catalysis. AMP bound to the PRA-CH domain mimics a part of the substrate, giving insights into the reaction mechanism. The latter interaction also arises as a possible second-tier regulatory mechanism of the HBP flux, as indicated by inhibition assays and isothermal titration calorimetry.
format	article
author	Wojciech Witek Joanna Sliwiak Milosz Ruszkowski
author_facet	Wojciech Witek Joanna Sliwiak Milosz Ruszkowski
author_sort	Wojciech Witek
title	Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
title_short	Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
title_full	Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
title_fullStr	Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
title_full_unstemmed	Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
title_sort	structural and mechanistic insights into the bifunctional hisn2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/ee8560a2ea2a4cecbc3b6682eea46ba7
work_keys_str_mv	AT wojciechwitek structuralandmechanisticinsightsintothebifunctionalhisn2enzymecatalyzingthesecondandthirdstepsofhistidinebiosynthesisinplants AT joannasliwiak structuralandmechanisticinsightsintothebifunctionalhisn2enzymecatalyzingthesecondandthirdstepsofhistidinebiosynthesisinplants AT miloszruszkowski structuralandmechanisticinsightsintothebifunctionalhisn2enzymecatalyzingthesecondandthirdstepsofhistidinebiosynthesisinplants
_version_	1718389604985339904

Structural and mechanistic insights into the bifunctional HISN2 enzyme catalyzing the second and third steps of histidine biosynthesis in plants

Ejemplares similares