SMITH (Smith), Hamilton

genus. August 23, 1931
American expert on molecular biology and genetics Otanel Hamilton Smith was born in New York, the son of Bunny Smith (Otanel) and Tommy Smith Harku, except Hamilton, the family had another child. His father taught at New York pedagogy students at Columbia University in the summer months. The rest of the time, the family spent in Geynsvile (Florida), where the father and. served as assistant professor of pedagogy at the University of Florida. In 1937, Mr.. Smith, Sr., received his doctoral degree, switched to teaching at University of Illinois and the family moved to Urbano.
While studying at a state school in Urbana with. involved in athletics and was interested in chemistry and electronics. He spent many hours in a chemical laboratory, which he and his brother rigged the equipment purchased for the money they earned. In 1948, having completed just three years of secondary school, university, P. enrolled in the University of Illinois, to get the mathematical education. In 1950, Mr.. He joined the University of California at Berkeley to study the biology. Here C. first began to study cellular physiology, biochemistry and biology - things, caused him great concern.
In 1952, Mr.. S. received a bachelor's degree at Berkeley and enrolled in the College of Medicine, Johns Hopkins. In this college, he passed the usual course, and he had little opportunity to engage in research work. Four years later, he received a medical degree, after which he worked during the year intern at Barnes Hospital Washington University in St. Louis. In the same year he married Elizabeth Ann Chatter, who studied the profession of nurse. In the family they were born four sons and a daughter. In 1957. S. was drafted into the Navy of the United States and two years he served as senior medical officer at San Diego (California). At the same time he started in his spare time reading books on genetics.
After demobilization. 1960 to 1962. trained at Henry Ford Hospital in Detroit (Michigan). In his spare time he continued to explore the literature on genetics, and in particular on the genetics of bacteria, and biochemistry of nucleic acids. In 1962. he enrolled in doctoral studies at the National Institute of Health and began studying the genetics of bacteriophages and prophages in the workings of the department of Human Genetics, University of Michigan. Of particular interest he has aroused the processes of destruction of bacterial cells. particles of bacteriophages.
Bacteriophage - a virus that attacks bacterial cells, it is the simplest form of life, including the inner core of nucleic acids, and the outer protein shell. When the phage enters the bacterial cell, it can begin to multiply and cause its destruction by the release of new phage particles. In addition, it can be embedded into the genetic structure of bacterial cells formed deoxyribonucleic acid (DNA) - in this case it is called a prophage, - and passed on to daughter cells during division. Finally, the bacteriophage can be cleaved and inactivated enzyme systems of the bacterial cell, a phenomenon called restriction-modification system, controlled by a host cell.
. Restriction-modification occurs under the action of two enzymes of the bacterial cells - restriction endonucleases and methylases
. Restriction endonuclease recognizes a specific sequence of bases in nukleatidnyh bacteriophage DNA and cleaves this DNA into several fragments. Methylase also recognizes an identical sequence in the bacterial DNA (or DNA of the host cell), it methylates and thereby protects against enzymatic degradation own endonuclease. (Methylation - is adherence to the DNA molecule methyl group, consisting of one carbon atom and three hydrogen atoms.
Werner Arber, who worked in the 60-ies. University of Geneva, suggested that this system of two enzymes characteristic of all the bacterial cells. He called it a restriction-modification system, since under its influence is bacteriophage restriction and modification of the host cell. In addition, Arber discovered restriction endonucleases in the bacteria Escherichia coli, inhabiting the large intestine; this endonuclease cleaves the DNA of the phage in random or nonspecific sites. It was called the Type I endonuclease. Arber, predicted that other bacteria should be found by restriction endonucleases of type II, cleave the phage DNA at specific sites, and that these endonucleases will be useful for determining the genetic structure of DNA molecules.
. After working for two years at the University of Michigan, C
. was promoted to research fellow in the department of Microbiology, College of Johns Hopkins. Here he studied the enzymatic mechanisms of restriction-modification systems, which were previously investigated in conjunction with Arber during the year in Geneva.
Returning in 1967. college at Johns Hopkins, C. was promoted to assistant professor of microbiology, and two years later - Associate Professor. By this time, C. and his colleagues conducted a series of important experiments on the enzymes of restriction-modification system in bacteria Haemophilis influenzae. Having isolated and purified restriction endonucleases of type II, C. and his colleagues first identified a specific, ie. acting on certain sites, endonuclease. In addition, they established a specific nucleotide sequence of DNA, which recognizes this enzyme, and the plot on which it operates. Since then, it was found many specific enzymatic systems such as P. As the number of identified restriction-modification system grew, it became possible, as predicted by Arber, to analyze the gene structure of DNA molecules. Soon after the C. identified in pure form restriction endonuclease H. influenzae, one of his colleagues in the College of Johns Hopkins Daniel Nathan, using an open C. restriction endonucleases and other enzymes, found the exact localization and function of genes of DNA virus-40 monkeys.
Studies of restriction enzymes S., Arber, and Nathans, made it possible to conduct such an analysis of the chemical structure of genes. This has opened great prospects in the study of higher organisms. Through this work, scientists now have the opportunity to address the critical problem of cell differentiation. In 1973, Mr.. S. was promoted to full professor of microbiology at the College, Johns Hopkins. In 1975. He became a board member of society Guttenheyma at the Institute of Molecular Biology, University of Zurich in Switzerland, where he worked during the year.
In 1978. S. with Arber and Nathans was awarded the Nobel Prize in Physiology or Medicine for the 'discovery of restriction enzymes and their use for solving problems of molecular genetics'. In the congratulatory speech, a researcher at the Karolinska Institute, Peter Reichardt said: 'Work winners this year, a new era in genetics'. He stressed that to achieve P. lies in the fact that he tested the hypothesis Arber of restriction enzymes. 'He singled out in its pure form is one of restriction enzymes and showed that this enzyme can cleave the foreign DNA. Today we know, probably about 100 of these enzymes. They all cleave DNA, each in different parts. With their help - continued Reichardt - these giant molecules can be divided into well-defined fragments, which can later be used for structural studies and genetic experiments. "
In 1981. S. was promoted to Professor of Molecular Biology and Genetics, College of Johns Hopkins and has since continued to explore the mechanisms of enzymatic systems of restriction-modification, . in particular the spatial (three dimensional) molecular mechanisms of interaction between DNA and endonuclease.,
. In his spare time from teaching and research time with
. likes to play the piano and listening to classical music. He was a passionate admirer of the pianist Artur Rubinstein. S. - Member of the National Academy of Sciences of the USA, . American Society for Microbiology, . American Society of Biochemistry and the American Association for the Advancement of Science, in addition, . He is a corresponding member of the American Academy of Arts and Sciences.,