# HISTORY 07 May 2016: Updated by: TOUCHUP-v1.18 17 Mar 2016: Updated by: TOUCHUP-v1.14 27 Mar 2016: Updated by: TOUCHUP-v1.15 # molecular_function 20140730: root_PTN000602759 has function adenosylhomocysteinase activity (GO:0004013) 20140730: Eumetazoa_PTN001158976 has LOST/MODIFIED function adenosylhomocysteinase activity (GO:0004013) # cellular_component 20140730: root_PTN000602759 is found in cytosol (GO:0005829) # biological_process 20140730: root_PTN000602759 participates in S-adenosylmethionine cycle (GO:0033353) # WARNINGS - THE FOLLOWING HAVE BEEN REMOVED FOR THE REASONS NOTED # NOTES Tree Major duplications to create AHCYL1/2 in animals, which diverge by duplication at base of vertebrates to L1 and L2. Checked the substrate specificity residues annotated in the human AHCY sequence and found all substrate binding residues are conserved in AHCYL1/2 clade but two of the NAD binding sites are not (residues 243 and 353 in human AHCY). Thus it is possible that these homologs have lost ACHY catalytic activity, and I will therefore infer this to be the case. Also found a review paper (PMID 24518248) on AHCYL1 homologs (also called IRBIT) and will add annotations in Protein2GO and can propagate these later. Interestingly, in this paper they cite literature that claims that the substrate binding site is not conserved but the NAD site is. Either way, the inference of loss of ancestral function holds. MF propagated only the enzymatic function as others are part of this same activity BP All non propagated annotations are covered by propagated MF or BP # 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).