molecular cloning and in silico analysis of a gtp cyclohydrolase i gene from grape ‎

An entire open reading frame (orf) encoding for a polypeptide of gtp cyclohydrolase i (gtpch i) was isolated and cloned from askari cultivar of grape (vitis vinifera l.) berries. the 1,338-nucleotide orf yields a 445-residue amino acid sequence with a calculated molecular mass of 48.65 kda and a predicted isoelectric point of 6.43. the vvgtpch i genomic sequence with a length of 4,964 bp contains two exons (169 and 1,169 bp) and an intron (2,676 bp). the gtpch i sequence of grape displayed a strong similarity with gtpch i sequence found in other plants, including peach (72%), cocoa (72%), strawberry (70%), and poplar (69%). analysis of mrna secondary structure revealed that the start codon of vvgtpch i is completely exposed, suggesting a robust binding of the ribosome and efficient translation. similar to gtpchs i from  diverse sources, molecular modeling uncovered that the monomer of vvgtpch i adopts an αβ structure, which includes 10 α-helices and 8 β-sheets. moreover, in silico analysis of the vvgtpch i gene promoter identified potential cis-acting elements  responsive to environmental signals. this suggests that the vvgtpch i gene has the capacity to be responsive to various environmental cues, such as heat, heavy metals, light, and plant hormones.