We report here the primary structures and sequence analysis of the human ribosomal protein L39 (hRPL39) and S27 (hRPS27). The hRPL39 cDNA is 352 bp in size encoding a predicted protein of 51 amino acids. The region KRRHWRRTKL near the carboxyl end is conserved between human, rat, maize, C. elegans and yeast. The hRPS27 cDNA is 321 bp in size encoding a deduced protein of 84 amino acids. When the deduced amino acid sequence of hRPS27 was compared with that of rat ribosomal protein S27 and human metalloproteinstimulin-1 (MPS-1), identity levels of 96.4% and 100% were obtained respectively. A potential polyadenylation signal AACAAA is found in the MPS-1 cDNA but the more frequently used AATAAA sequence is present in the hRPS27 cDNA. The carboxyl-terminal cysteine arrangement in hRPS27 is similar to the family of C4 zinc finger DNA-binding proteins.