1. A User’s Guide to GO: Structural and Functional Annotation

2. Genomic Annotation
Genome annotation is the process of attaching biological information to genomic sequences. It consists of two main steps:
identifying functional elements in the genome: “structural annotation”
attaching biological information to these elements: “functional annotation”
biologists often use the term “annotation” when they are referring only to structural annotation

3. Structural annotation:
DNA annotation
CHICK_OLF6
Protein annotation
TRAF 1, 2 and 3
TRAF 1 and 2
Data from Ensembl Genome browser

4. Functional annotation:
catenin

5. Structural & Functional Annotation
Structural Annotation:
Open reading frames (ORFs) predicted during genome assembly
predicted ORFs require experimental confirmation
the Sequence Ontology (SO) provides a structured controlled vocabulary for sequence annotation
Functional Annotation:
annotation of gene products = Gene Ontology (GO) annotation
initially, predicted ORFs have no functional literature and GO annotation relies on computational methods (rapid)
functional literature exists for many genes/proteins prior to genome sequencing
GO annotation does not rely on a completed genome sequence!

6. Genomic Annotation Ontologies
Ontologies define classes of biological terms & show how they relate to each other
human readable term names
computer mineable (large datasets)
Structural annotation:
Sequence Ontology (SO)
Functional annotation:
Gene Ontology (GO)
molecular function, biological process, cellular process