Comparative Analysis of AGPase Genes and Encoded Proteins in Eight Monocots and Three Dicots with Emphasis on Wheat.
ADP-glucose pyrophosphorylase (AGPase) is a heterotetrameric enzyme with two large subunits (LS) and two small subunits (SS). It plays a critical role in starch biosynthesis. We are reporting here detailed structure, function and evolution of the genes encoding the LS and the SS among monocots and dicots. "True" orthologs of maizeSh2(AGPase LS) andBt2(AGPase SS) were identified in seven other monocots and three dicots; structure of the enzyme at protein level was also studied. Novel findings of the current study include the following: (i) at the DNA level, the genes controlling the SS are more conserved than those controlling the LS; the variation in both is mainly due to intron number, intron length and intron phase distribution; (ii) at protein level, the SS genes are more conserved relative to those for LS; (iii) "QTCL" motif present in SS showed evolutionary differences in AGPase belonging to wheat 7BS,T. urartu, rice and sorghum, while "LGGG" motif in LS was present in all species exceptT. urartuand chickpea; SS provides thermostability to AGPase, while LS is involved in regulation of AGPase activity;(iv)heterotetrameric structure of AGPase was predicted and analyzed in real time environment through molecular dynamics simulation for all the species; (v) several cis-acting regulatory elements were identified in the AGPase promoters with their possible role in regulating spatial and temporal expression (endosperm and leaf tissue) and also the expression, in response to abiotic stresses; and (vi) expression analysis revealed downregulation of both subunits under conditions of heat and drought stress. The results of the present study have allowed better understanding of structure and evolution of the genes and the encoded proteins and provided clues for exploitation of variability in these genes for engineering thermostable AGPase.
Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh University Meerut, India.
Ritu
R
Batra
Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh University Meerut, India.
Gautam
G
Saripalli
Department of Crop and Soil Sciences, Washington State University Pullman, WA, USA.
Amita
A
Mohan
Department of Bioinformatics, Indian Institute of Information Technology-Allahabad Allahabad, India.
Saurabh
S
Gupta
Department of Crop and Soil Sciences, Washington State University Pullman, WA, USA.
Kulvinder S
KS
Gill
Department of Bioinformatics, Indian Institute of Information Technology-Allahabad Allahabad, India.
Pritish K
PK
Varadwaj
Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India; Molecular Biology Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh UniversityMeerut, India.
Harindra S
HS
Balyan
Bioinformatics Infrastructure Facility (BIF) Laboratory, Department of Genetics and Plant Breeding, Ch. Charan Singh University Meerut, India.
Pushpendra K
PK
Gupta
ADP_Glucose_PP domain; AGPase; expression analysis; genes structure; ligand binding; molecular dynamics simulation; promoter analysis