Nucleoside triphosphate pyrophosphatase that hydrolyzes 7-methyl-GTP (m(7)GTP) (PubMed:24210219). May have a dual role in cell division arrest and in preventing the incorporation of modified nucleotides into cellular nucleic acids (PubMed:24210219). H2O + N(7)-methyl-GTP = diphosphate + H(+) + N(7)-methyl-GMP kcat is 1.2 sec(-1). Monomer and homodimer. Belongs to the Maf family. YceF subfamily. Extended N-terminus.