Catalysis of the reaction: 10-formyltetrahydrofolate + N1-(5-phospho-D-ribosyl)glycinamide = tetrahydrofolate + N2-formyl-N1-(5-phospho-D-ribosyl)glycinamide.
5,10-methenyltetrahydrofolate:2-amino-N-ribosylacetamide ribonucleotide transformylase activity