In the early morning of August 2 1 Beijing time, the history research group published two papers online in the famous journal Science-the structure of 3.6-angstrom splice and the structural basis of precursor messenger RNA splicing, announcing that the high-resolution three-dimensional structure of the splice and the basic working mechanism of the splice splicing precursor messenger RNA have been obtained.
"Stone Laboratory has challenged this almost impossible task in the field of life science and achieved success on the world stage." Ding Shao Patel, an academician of the American Academy of Sciences and a famous structural biologist, commented on this. More importantly, "the splicing structure was completely completed by China scientists in China with the most advanced technology, which is a milestone in the development of life science in China."
Fu Xiangdong, a professor in the Department of Cell and Molecular Medicine at the University of California, San Diego, believes that this research is "China's greatest contribution to world science in the field of basic life sciences in the past 30 years". Shi has been immersed in scientific research for 25 years, and has published nearly 50 papers as a correspondent in three magazines: Nature, Science and Cell. In his view, this discovery may be his most important research achievement so far.
Impossible Mission
1956, British biologist Crick put forward a central rule in the field of molecular biology, describing that all biological processes are information flows from DNA to RNA and then to protein.
The emergence of several Nobel Prizes stems from the discovery and elaboration of the central principle. For example, the structural analysis of RNA polymerase and ribosome won the Nobel Prize in 2006 and 2009 respectively. As a huge and complex dynamic molecular machines, the structural analysis of splice is generally considered to be more difficult than RNA polymerase and ribosome. At the same time, because many human diseases can be attributed to the wrong splicing of genes or the wrong regulation of splices, the structural analysis of splices has always been considered as one of the hottest and most anticipated structural biology studies.
From 65438 to 0995, Shi went to Yale University for an interview. His boss is Tom Stec, and he and two other scientists won the 2009 chemistry prize for their analysis of ribosome structure. Stites's research later won him the Nobel Prize. One of his postdoctoral researchers told Shi: "What Stites wants to do most is splicing."
Splicing, the jewel in the crown of molecular biology, is the ultimate dream of many biologists. However, this "naughty guy is complex, dynamic and changeable". Under the technical conditions at that time, no scientist could clearly "capture" it.
From 65438 to 0998, Shi went to teach at Princeton University, and this dream was hidden in his heart. With the accumulation of qualifications and experience, Shi began to study membrane proteins in 2004. But he still dared not touch the splicing. "It was a dream." .
In 2005, Rao He Zi, an academician of China Academy of Sciences and a famous biologist, co-published a paper in Cell magazine. He accidentally received a phone call from another famous biologist, Professor Rao Yi of Northwest University. Rao Yi made a suggestion: Next, you should do the research of splicing.
Rao He Zi's answer is very solid: I dare not touch it. This was the idea of many biologists at that time. Shi said, "There is no way or means."
Young people challenge old brands.
However, the fire of dreams never goes out.
In 2007, Shi returned to work in the Biology Department of Tsinghua University. His laboratory has been opened, but he still hasn't touched this dream: students can't be trained with such topics, otherwise they will only be disappointed and even lose interest in scientific research.
"It's too dangerous. You may get nothing. Students cannot be allowed to be cannon fodder. " He speaks frankly.
At that time, he had a more realistic problem to worry about: he stayed abroad for a long time and wondered if he could make anything with domestic water and reagents.
At the beginning of returning to China, it often happens that the cultured bacteria are accidentally contaminated; Spread the board on the experimental platform, and there will be all kinds of miscellaneous bacteria the next day.
Shi also put more energy into cultivating students' molecular biology and biochemistry.
After a year of construction, Shi's first article was published after he returned to Tsinghua to teach in 2008. Although it has not been published in top magazines, well-trained students are confident.
At this time, the technological revolution that can capture splicing is already in its infancy.
There are three sharp tools in the study of structural biology: X-ray crystal diffraction, nuclear magnetic resonance and single particle frozen electron microscope (frozen electron microscope). However, because of its low resolution, cryoelectron microscope is considered as the weakest technical means among the three sharp weapons.
In 2007, frozen electron microscope technology was far from being developed, so Tsinghua chose to focus on developing frozen electron microscope technology. In 2009, although the conditions were not perfect at that time, Shi decided to start his own dream. "If the conditions are met, the day lily will be cold." One of his postdocs and two doctoral students entered the field of splicing.
In this field, Shi's team is the real younger generation: there are seven laboratories in the world leading the research direction in this field, including the molecular biology laboratory of Cambridge University in England, which is the foundation of modern structural biology and molecular biology and won 14 Nobel Prize winners.
Faced with these powerful competitors at home and abroad, some doctoral students questioned: Can we really do this project well?
So from the beginning, they chose to start small, trying to analyze the structure of some important protein in the splicing complex, and gradually approached the goal. This process is not easy. "We have been working very hard." Shi said that even for a long time, students had no achievements and were under great pressure. To Shi's relief, they are all "calm".
20 13 cryo-electron microscope technology has made a breakthrough in software analysis photography technology and image processing technology. "The original contribution of cryoelectron microscopy and X-ray crystal diffraction to structural biology was 1: 10, and this ratio was almost reversed in the past year." Shi said, "Without the innovation of cryo-electron microscope technology, it is completely impossible to obtain near-atomic splicing resolution."
Along with growth, there are also research conditions in the field of life sciences. In 2007, there were only 43 independent laboratories in the biology department at the time of the express train, and now there are 140. A large number of young people have joined the army of life science, which has brought great vitality to life science in Tsinghua University. Yan Chuangye, a 30-year-old postdoctoral fellow at the School of Life Sciences of Tsinghua University, Hang Jing, a 26-year-old doctoral student at Tsinghua University Medical College, and Wan, a 25-year-old doctoral student, are among them.
At the beginning of the year, the team reported Lsm heptamer, an important component of splicing complex, and its crystal structure in RNA binding state for the first time. The article was published in Nature, but it is still far from their goal.
"We want to layout, also want to method. You can't just do things with tools, you must understand these tools. " Stone said to.
This kind of waiting is really too long.
On June 24th, a paper by Gai Na Research Group of Molecular Biology Laboratory of Cambridge University, which has the most say in this field, was published online on the website of Nature magazine. The result once caused a sensation: they improved the resolution of tri-snRNP, the central compound involved in the splicing process, to 5.9 angstroms. Previously, the accuracy of human understanding of gene splicing was only 29 angstroms.
1 angstrom is equivalent to one billionth of a meter. Gai Na's work has made a leap, but he can only see the secondary structure of protein, but can't see amino acids.
The research results of Shi team not only improved the accuracy from 5.9 angstroms to 3.6 angstroms, but also made many amino acids clearly visible. More importantly, the object of analysis is the real splice, not the compounds involved in the assembly process of the splice obtained by Gai Na's team. This is the first time to see the details of stitching at near atomic resolution.
Jack Shosdeck, a professor at Harvard Medical School and winner of the 2009 Nobel Prize in Physiology and Medicine, commented that "the splice is the last super-large complex in the cell that needs to be analyzed, and this waiting has been too long".
In fact, this is an unexpected breakthrough in history.
The reason is that Wanhe Hangjing domesticated these samples in various ways, making them suitable for electron microscope observation. Another reason lies in Yan Chuangye's ingenious innovation in computing software, so that all important particles can be re-selected. On the day this paper was published in Science Online, the first email Shi received was from a Daniel in the field of cryoelectron microscopy, asking for this program script.
In fact, in April of this year, Shi was simply dreaming of the moon. At first, he told Yan Chuangye, 15 angstrom, we can do it. If we do it at 10 angstrom, we'll find a place to post an article and tell this venue that we came first. Unexpectedly, this limit was broken again and again: first 12 angstrom, then 8 angstrom, then 5.6 angstrom, then 3.9 angstrom, and finally 3.6 angstrom.
The joy of this major scientific breakthrough is irreplaceable by any award. The writing of this paper also created the first time in the 25-year scientific research career: the first time I wrote an article until I couldn't sleep at night.
Just over two months ago, in the final sprint stage of the research, Shi took three students to "write papers desperately". During that time, he wrote papers until the early hours of the morning every day. Sometimes he went home after 6 o'clock, slept until 8 o'clock, and then got up to write. It took four hours to write a paper on the train to send the children back to their hometown in Henan. So that at 3 o'clock one morning, Shi, who was still writing a paper in the office, suddenly had a cramp in his coccyx and couldn't move. This frightened the students who also wrote papers in the laboratory. After the rest, I walked a few laps before Shi recovered.
The professor at the School of Pharmacology of Duke University in the United States believes that this research by the history team has solved "the basic biological problems that countless scientists yearn for". In his view, his achievements "will be seriously considered by the Nobel Committee".
The media have speculated whether this will be a breakthrough in China's natural science field in the Nobel Prize.
Gao Fu, academician of China Academy of Sciences and deputy director of China Center for Disease Control and Prevention, hopes that the media will show mercy. "They have pointed out the direction for scientists all over the world. The Nobel Prize is not something that a public team should do. For science, there is no best, only better. For them, the most important thing is to be interested in exploration and constantly discover unknown curiosity. "
Shi's team has just begun to explore splicing passwords. "The core significance of this work is to let human beings have a further understanding of the process and mechanism of life." Shi's next task is to see clearly the differences between different splicing, so as to explain the molecular mechanism of intron removal and exon splicing. (Beijing, August 23rd, by reporter Chunlin Yuan)