library(Biostrings)

download.file('https://ftp.ncbi.nlm.nih.gov/genomes/all/GCF/003/972/325/GCF_003972325.1_ASM397232v1/GCF_003972325.1_ASM397232v1_cds_from_genomic.fna.gz'
              'genomic.fna.fz')
genome = readDNAStringSet('genome.fna.gz')