# HISTORY
26 Mar 2016: Updated by: TOUCHUP-v1.15
16 Mar 2016: Updated by: TOUCHUP-v1.14

# molecular_function

# cellular_component
20140513: Eukaryota_PTN000423400 is found in proteasome complex (GO:0000502) 
20140513: Eukaryota_PTN000423400 co-localizes with nucleus (GO:0005634) 

# biological_process
20140509: Eukaryota_PTN000423400 participates in double-strand break repair via homologous recombination (GO:0000724) 
20140513: Eukaryota_PTN000423400 participates in proteolysis (GO:0006508) 
20140509: Basidiomycota_PTN001047762 does NOT participate in double-strand break repair via homologous recombination (GO:0000724) 
20140509: Eukaryota_PTN001047770 does NOT participate in double-strand break repair via homologous recombination (GO:0000724) 
20140509: node_PTN000423452 does NOT participate in double-strand break repair via homologous recombination (GO:0000724) 

# WARNINGS - THE FOLLOWING HAVE BEEN REMOVED FOR THE REASONS NOTED

# NOTES
BRCA2 is a breast cancer susceptibility gene implicated in the repair of double-strand breaks by homologous recombination with RAD51. DSS1 is required for the BRCA2-RAD51 complex to become associated with sites of DNA damage. DSS1 is involved in DNA damage repair via homologous recombination.
Although Human_SHFM1 has an annotation to peptidase activity GO:0008233, the paper reporting the IDA does not seem to have any claims of peptidase activity, or any of its synomyms (hydrolase, acting on peptide bonds;  peptide hydrolase activity;  protease activity; proteinase activity). The paper reports that:
Yeast and mammalian two-hybrid assays showed that DSS1 can associate with BRCA2 in the region of amino acids 2472 to 2957 in the C terminus of the protein. Using coimmunoprecipitation of epitope-tagged BRCA2 and DSS1 cDNA constructs transiently expressed in COS cells, authors demonstrated an association. Furthermore, endogenous BRCA2 could be coimmunoprecipitated with endogenous DSS1 in MCF7 cells, demonstrating an in vivo association. No further details on the nature of the bond are discussed. Should this term be removed? or changed to 'catalytic avtivity' instead?
The human Sem1 homologue hDSS1 was found to be a functional homologue of Sem1 and capable of interacting with the human 26 S proteasome. The results suggest that Sem1, possibly hDSS1, is a novel subunit of the 26 S proteasome and plays a role in ubiquitindependent proteolysis.
The reason for annotating these clades as "NOT" for double-strand break repair via homologous recombination (GO:0000724)  is that ORYSJ_P0693B08.32 and PUCGT_PGTG_08936 have long (20 - 40 aa) strings of residues interrupting the conserved domain of DSS1, which in turns increases the length of the peptide, which has been very well characterized to 71aa in length. Additionally TETTS_TTHERM_00227230 has an extended string of ~40 aa at the beginning of the protein, and the second portion of its conserved domain is severely degenerate in comparison to all other proteins in the family.

# REFERENCE
Annotation inferences using phylogenetic trees
The goal of the GO Reference Genome Project, described in PMID 19578431, is to provide accurate, complete and consistent GO annotations for all genes in twelve model organism genomes. To this end, GO curators are annotating evolutionary trees from the PANTHER database with GO terms describing molecular function, biological process and cellular component. GO terms based on experimental data from the scientific literature are used to annotate ancestral genes in the phylogenetic tree by sequence similarity (ISS), and unannotated descendants of these ancestral genes are inferred to have inherited these same GO annotations by descent. The annotations are done using a tool called PAINT (Phylogenetic Annotation and INference Tool).