Biology 1002B Lecture Notes - Lecture 19: Open Reading Frame, Dna Annotation, Sequence Alignment
Document Summary
Lecture 19: molecular homology: strategies for determining if features are homologous. Evolution and selection act on phenotype and not genotype. Gene sequences can change but not necessarily affect phenotype. National center for biotechnology information gene database. Comparative genomics: sequence genomes genome annotation protein prediction align sequences determine homology. Genome annotation: ascribe biological function and meaning to sequence, gene/protein prediction. Don"t sequence proteins anymore through purification and isolation: regulatory elements or biological function through similarity searches, automated algorithms. Protein coding gene prediction/deduction: which of the 6 possible reading frames are the most probable. Sequence alignment: blast local (common) Faster and stronger: clustral global. Start at beginning of protein coding sequence. Tries to align all similar bases by adding gaps to try to get them to align. Slower and weaker: sequences detected by annotation programs to detect open reading frames (orf) Computers looks for the longest open reading frame.