Catabolism of the methyl derivatives of adenosine and cytidine in staphylococci

Products of 1-methyladenosine, 2'-O-methyladenosine, 2'-O-methylcytidine, a nd 5-methylcytidine catabolism by resting cells of Staphylococcus aureus an d Staphylococcus intermedius were chromatographically separated. The methyl group in 1-methyladenosine protected the adenosine derivative from deamina tion by S. intermedius but it did not protect N-glycosidic bond from cleava ge by S. intermedius and S, aureus. The methyl group in 2'-O-methyladenosin e and 2'-O-methylcytidine protected the N-glycosidic, bond from cleavage by S. aureus and S. intermedius but it did not protect the adenosine and cyti dine derivatives from deamination by S. intermedius. 5-Methylcytidine was c onverted by the common route in which 5-methylcytidine was first deaminated to ribothymidine which was cleaved to yield thymine. S. intermedius deamin ated the purine and pyrimidine ribonucleosides adenosine, 2'-O-methyladenos ine, cytidine, and 5-methylcytidine. Pyrimidine ribonucleosides (cytidine, 5-methylcytidine) were deaminated only slowly and purine ribonucleosides (a denosine, 2'-O-methyladenosine) not at ail by S. aureus.