No abstract

Determining the primary sequences of informational macromolecules is no longer a limiting factor for our ability to completely understand the biological functioning of cells and organisms. Similarly, our understanding of transcriptional regulation (transcriptomics) has been greatly enhanced by the availability of microarrays. Our next hurdle is to learn the biochemical functions of all the gene products (proteomics) and the totality of all the interactions among them (interactomics). Using traditional biochemical methods, this will take a very long time. More efficient methods are needed to address these questions, or at least to suggest possible candidates for further testing. High-resolution imaging using molecule-specific tags will reveal details of cellular architecture that are expected to provide additional insights and clues about the interactions and functions of many gene products. Computer modeling of macromolecular structures and functional systems will be of key importance. We present here a brief historical and futuristic perspective of genomics and some of its other 'omics offshoots in the post-genomic era.

Escherichia coli K-12 has two genes, asnA+ and asnB+, either one of which is able to satisfy the need of cells for asparagine. In order for a strain to have an auxotrophic requirement for asparagine, both genes must be mutationally inactivated. We obtained mutants with Tn5 inserted in asnB. asnB was mapped by conjugation and by three-factor P1 transductions at 15 min on the E. coli K-12 linkage map, between ubiF and nagB. Specialized transducing phage X781 supE was shown to carry asnB, as well as supE, ubiF, nagA, and nagB. asnA is the previously mapped ilv-linked asn locus, which is between uncB and rbs. E. coli C also has two asn genes, corresponding to asnA and asnB.