"Ричард Фейнман. Surely You're Joking, Mr. Feynman!/Вы, конечно, шутите, мистер Фейнман! (англ.)" - читать интересную книгу автораif the back mutations occurred in the same place on the DNA spiral. With
great care and a lot of tedious work I was able to find three examples of back mutations which had occurred very close together - closer than anything they had ever seen so far - and which partially restored the phage's ability to function. It was a slow job. It was sort of accidental: You had to wait around until you got a double mutation, which was very rare. I kept trying to think of ways to make a phage mutate more often and how to detect mutations more quickly, but before I could come up with a good technique the summer was over, and I didn't feel like continuing on that problem. However, my sabbatical year was coming up, so I decided to work in the same biology lab but on a different subject. I worked with Matt Meselson to some extent, and then with a nice fella from England named J. D. Smith. The problem had to do with ribosomes, the "machinery" in the cell that makes protein from what we now call messenger RNA. Using radioactive substances, we demonstrated that the RNA could come out of ribosomes and could be put back in. I did a very careful job in measuring and trying to control everything, but it took me eight months to realize that there was one step that was sloppy. In preparing the bacteria, to get the ribosomes out, in those days you ground it up with alumina in a mortar. Everything else was chemical and all under control, but you could never repeat the way you pushed the pestle around when you were grinding the bacteria. So nothing ever came of the experiment. Then I guess I have to tell about the time I tried with Hildegarde The question was whether the ribosomes of bacteria can manufacture the proteins of humans or other organisms. She had just developed a scheme for getting the ribosomes out of peas and giving them messenger RNA so that they would make pea proteins. We realized that a very dramatic and important question was whether ribosomes from bacteria, when given the peas' messenger RNA, would make pea protein or bacteria protein. It was to be a very dramatic and fundamental experiment. Hildegarde said, "I'll need a lot of ribosomes from bacteria." Meselson and I had extracted enormous quantities of ribosomes from E. coli for some other experiment. I said, "Hell, I'll just give you the ribosomes we've got. We have plenty of them in my refrigerator at the lab." It would have been a fantastic and vital discovery if I had been a good biologist. But I wasn't a good biologist. We had a good idea, a good experiment, the right equipment, but I screwed it up: I gave her infected ribosomes - the grossest possible error that you could make in an experiment like that. My ribosomes had been in the refrigerator for almost a month, and had become contaminated with some other living things. Had I prepared those ribosomes promptly over again and given them to her in a serious and careful way, with everything under control, that experiment would have worked,, and we would have been the first to demonstrate the uniformity of life: the machinery of making proteins, the ribosomes, is the same in every creature. We were there at the right place, we were doing the right things, but I was doing things as an amateur - stupid and sloppy. You know what it reminds me of? The husband of Madame Bovary in |
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