Biology Reference
In-Depth Information
Cut DNA
molecules with
restriction enzyme
to generate
complementary
sequences on the
vector and the
fragment
Chromosomal DNA
Fragment To Be Cloned
Vector DNA
Join vector and chromosomal
DNA fragment using the enzyme
DNA ligase
Recombinant DNA Molecule
Introduce into bacterium
Recombinant DNA
Molecule
Bacterial
Chromosome
Figure 4:
Cloning DNA in plasmids. Courtesy U.S. Department of Energy Genomic Science program and the website http://
genomicscience.energy.gov.
many more individual Universities and Research Centres all over the world. Various aspects of
computer methods in sequence analysis from database searching, performing multiple sequence
alignment, construction of phylogenetic trees to predicting protein structure and function have been
reviewed (Doolittle, 1996). The fi rst such search tool was developed by Altschul
et al
. (1990) known
as basic local alignment search tool (BLAST). A number of new generation, powerful and sensitive
bioinformatics tools are made available subsequently (Henikoff and Henikoff, 1997; Neuwald
et al
.,
1997; Altschul
et al
., 1997). The BLAST programme is available for public use at NCBI website http://
blast.ncbi.nlm.nih.gov/Blast.cgi that helps in the identifi cation of nucleotide sequences (BLASTn),
protein sequences (BLASTp) and compares translational products of a nucleotide sequence of both
strands against a protein database (BLASTx), searches a translational nucleotide database using a
protein query (TLASTn) and converts nucleotide query sequence into protein sequences (TBLASTx).
Other programmes used are based on interpolated Markov models (Salzberg
et al
., 1998) and coding
