Spc operon

Some archaeal r-protein operons contain open reading frames (ORFs) that are not present in the equivalent bacterial operon. In many cases, these ORFs code for proteins which show sequence similarity to eucaryal r-proteins. For example, ORF c, d and e in the spc operon of Methanococcus vannielii [100] and Sulfolobus acidocaldarius [Kusser et al., unpublished] code for r-proteins equivalent to the eucaryal r-proteins S4 Rattus norwegicus), L32 Homo sapiens) and LI9 R. norwegicus) respectively. 

Tamura H, Hotta Y, Sato H. Novel accurate bacterial discrimination by MALDl-Time-of-Flight MS based on ribosomal proteins coding in SlO-Spc-Alpha operon at strain level SIO-GERMS. J Am Soc Mass Spectrom. 2013 24(8) 1185-93. 

Hotta Y Teramoto K, Sato H, Yoshikawa H, Hosoda A, Tamura H. Classification of genus Pseudomonas by MALDI-TOF MS based on ribosomal protein coding in SlO-spc-alpha operon at strain level. J Proteome Res. 2010 9 6722-8. 

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