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.