Over the past decade, our laboratory and others have been concerned with molecular archaeological studies aimed at revealing the origins and evolutionary histories of permeases (1). These studies have revealed that several different families, defined on the basis of sequence similarities, arose independently of each other, at different times in evolutionary history, following different routes. When complete microbial genomes first became available for analysis, we adapted p- existing software and designed new programs that allowed us quickly to identify probable transmembrane proteins, estimate their topologies and determine the likelihood that they function in transport (2). This work allowed us to expand previously-recognized families and to identify dozens of new families. All of this work then led us to attempt to design a rational but comprehensive classification system that would be applicable to the complete complement of transport systems found in all living organisms (3). The classification system that we have devised is based primarily on mode of transport and energy coupling mechanism, secondarily on molecular phylogeny, and lastly on the substrate specificities of the individual permeases (4).

Autorentext

Jane K. Setlow, PhD. has championed the field of genetics for over 30 years, agreeing to edit Genetic Engineering: Principles & Methods since its inception in 1979. An internationally recognized scientist with numerous publications, Dr. Setlow is the former Chairperson of the NIH Recombinant DNA Molecule Advisory Committee (RAC). Her lab can found at Brookhaven National Laboratory, Upton, New York.

Inhalt

Evolution of Transport Proteins; M.H. Saier, Jr. Mechanisms of Apoptosis Repression; C.C.Q. Vu, J.A. Cidlowski. Cytokine Activation of Transcription; K.A. Mowen, M. David. Enzymatic Approaches to Glycoprotein Synthesis; P. Sears, et al. Vector Design and Development of Host System for Pseudomonas; H.P. Schweizer, et al. Genetic and Biochemical Studies on the Assembly of an Enveloped Virus; T.L. Tellinghuisen, et al. Enzyme and Pathway Engineering for Suicide Gene Therapy; M.E. Black. Deconstructing a Conserved Protein Family: the Role of MCM Proteins in Eukaryotic DNA Replication; S.G. Pasion, S.L. Forsburg. Expression of Foreign Genes in the Yeast Pichiapastoris; G.P. Lin Cereghino, et al. Protein Splicing and its Applications; I. Giriat, et al. Global Transcript Expression Profiling By Serial Analysis of Gene Expression (SAGE); H.S. Scott, R. Chrast. Index.