This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Caliciviruses are important human and animal pathogens causing a wide variety of diseases. The Calciviridae family consists of 4 genera (Norovirus, Sapovirus, Vesivirus and Lagovirus). Recently the complete genomic sequence of an enteropathogenic bovine calicivirus (Nebraska strain) has revealed that represents a fifth genus of Caliciviridae. Here we report the partial genomic sequence (5,539 bp) of a new calicivirus (Tulane) that was detected in stool samples of rhesus monkeys by RT-PCR. Genomic analysis of the Tulane virus revealed 3 major open reading frames (ORFs) with conserved amino acid sequence motifs, that are characteristic to all known caliciviruses, including GXXGXGKT (NTPase), EYXEX (Vpg), GDCG (3C-protease), GLPSG and YGDD (RdRp) within ORF1. ORF2 (VP1) encodes for a 534 aa protein and ORF3 (VP2) for a basic, 218 aa protein (pI = 10). Multiple alignments of individual proteins edited for retaining the maximum number of conserved evolutionary sites revealed 6% to 39% amino acid sequence homology between the Tulane virus and other calicviruses. The lowest homology was observed in the VP2 region (6-24%) and the highest in the NTPase region (25-39%). Phylogenetic trees constructed for the NTPase, 3C-protease, RdRp, VP1 and VP2 consistently placed the Tulane virus on a branch rooted together with the Norovirus genus but with distances equal to those between any other genera. Accordingly the Tulane virus represents a new calicivirus genus. Development of diagnostic assays that will enable epidemiological screening for the presence of Tulane-like caliciviruses among non-human primates and other species is under way.
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