CRISPR-associated Proteins
RAST and JGI agree that our genome has 6 CRISPR-associated (cas) proteins:
1) Cas1
2) Cas2
3) Cas3(helicase)
4) Cas4a (RecB family exonuclease)
5) TM1800 family
6) TM1801 family
After comparing the conserved proteins between our genome and the other 9 genomes, I found these cas-proteins were conserved:
H. sinaiiensis shares all 6 cas-proteins with H. mukohataei.
H. vallismortis shares all cas-proteins except for Cas4.
H. californiae shares all cas-proteins except for Cas4.
H. denitrificans shares all 6 cas-proteins with H. mukohataei.
H. mediteranei shares all 6 cas-proteins with H. mukohataei.
H. volcanii shares only Cas2, Cas3 and Cas4 with H. mukohataei.
H. sulfurifontis shares only Cas1, Cas3 and TM1800.
H. mucosum shares all 6 cas-proteins with H. mukohataei.
H. utahensis shares all 6 cas-proteins with H. mukohataei.
Research:
Several papers agree that Cas1 in particular is highly conserved across genomes. Only H. volcanii does not share the Cas1 gene with the other 9 genomes.
Usually found usually in the order cas3-cas4-cas1-cas2.
Huzzah! Our genome's Cas-proteins appear in the same order! (Well....2-1-4-3...but still!)
"CRISPR sequences have been found to be flanked by protein genes named cas (CRISPR-associated) genes and their encoded proteins are therefore called CAS proteins [2]. They are typically organized in small clusters and are associated with specific subtypes of CRISPRs. The number of cas genes associated with CRISPR subtypes is also variable, ranging from 6 to more than 20. The specific domains of CAS proteins have been predicted to harbor nuclease, helicase, recombinase, integrase and RNA and/or DNA binding activities [6] and [7]."SSO1450 – A CAS1 protein from Sulfolobus solfataricus P2 with high affinity for RNA and DNA
