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Accurate prediction of protein structures and interactions using a three-track neural network

Science

In 1972, Anfinsen won a Nobel prize for demonstrating a connection between a protein's amino acid sequence and its three-dimensional structure. Since 1994, scientists have competed in the biannual Critical Assessment of Structure Prediction (CASP) protein-folding challenge. Deep learning methods took center stage at CASP14, with DeepMind's Alphafold2 achieving remarkable accuracy. Baek et al. explored network architectures based on the DeepMind framework. They used a three-track network to process sequence, distance, and coordinate information simultaneously and achieved accuracies approaching those of DeepMind. The method, RoseTTA fold, can solve challenging x-ray crystallography and cryoโ€“electron microscopy modeling problems and generate accurate models of protein-protein complexes. Science , abj8754, this issue p. [871][1] DeepMind presented notably accurate predictions at the recent 14th Critical Assessment of Structure Prediction (CASP14) conference. We explored network architectures that incorporate related ideas and obtained the best performance with a three-track network in which information at the one-dimensional (1D) sequence level, the 2D distance map level, and the 3D coordinate level is successively transformed and integrated. The three-track network produces structure predictions with accuracies approaching those of DeepMind in CASP14, enables the rapid solution of challenging x-ray crystallography and cryoโ€“electron microscopy structure modeling problems, and provides insights into the functions of proteins of currently unknown structure. The network also enables rapid generation of accurate protein-protein complex models from sequence information alone, short-circuiting traditional approaches that require modeling of individual subunits followed by docking. We make the method available to the scientific community to speed biological research. [1]: /lookup/doi/10.1126/science.abj8754


Banking on protein structural data

Science

In 1953, the proposed structure of DNA magnificently linked biological function and structure. By contrast, 4 years later, the first elucidation of the structure of a proteinโ€”myoglobin, by Kendrew and colleaguesโ€”revealed an inelegant shape, described disdainfully as a โ€œvisceral knot.โ€ Additional complexity, as well as some general principles, was revealed as more protein structures were solved over the next decade. In 1971, scientists at Brookhaven National Laboratory launched the Protein Data Bank (PDB) as a repository to collect and make available the atomic coordinates of structures (seven at the time) to interested parties. The PDB now includes more than 180,000 structures, and this resource has fueled an incalculable number of advances, including the recent development of powerful structure prediction tools. Biology takes place in three dimensions, yet most biological information is stored in one-dimensional sequences of DNA that encode the amino acid sequences of proteins. The transition from one to three dimensions is accomplished through the spontaneous folding of a sequence of amino acids into a folded protein structure. Comparing elucidated structures revealed that proteins that are at least 30% identical in amino acid sequence almost always have the same folded structure; evolutionarily, structure is much more conserved than sequence. Conversely, some short stretches of five or more amino acids can adopt completely different structures; structure is context dependent. Thus, the relationship between sequence and structure is not a simple one. Predicting protein structures from sequences has been a grand challenge for decades. By 1994, fueled by the explosion of sequences, biophysicist John Moult and colleagues organized the first Critical Assessment of Structure Prediction (CASP) meeting. CASP is based on blinded assessments, which are common in clinical trials. Sequences of proteins whose structures had been determined but not publicly shared were made available to would-be predictors to develop and submit structural predictions for subsequent independent assessment. The first CASP meeting was somewhat depressing because the results revealed that predictors were doing substantially worse than they thought. CASP meetings have continued every 2 years and have driven the field forward through feedback and competition. The most recent CASP meeting, in November 2020, was shaken by results from the company DeepMind. Its AlphaFold program performed substantially better than other programs had in the past, producing many results that are of similar quality to that of experimental structures. The RoseTTA-Fold program, developed by the laboratory of structural biologist David Baker, builds on this laboratoryโ€™s previous work, combined with insights from the DeepMind success (see page 871). The results of both programs are sufficiently good that many are claiming that these represent relatively general (but certainly not perfect, and incomplete) solutions to the structure prediction problem. Notably, both groups have provided their computer code for their methods for others to use, test, and enhance. These programs are based on deep-learning artificial intelligence methods. Such approaches depend on the availability of many thousands of questions with known answers to train the neural networks at their core. Thus, without the sequences with known structures from structural biologists from around the world shared in the PDB, these approaches would not have been feasible. The teams that developed these powerful programs deserve great credit for their accomplishments, but these stand on a foundation of the results from billions of dollars of public fund investments in structural biology and the sustained support of the PDB from around the world (now overseen by the Worldwide PDB). Policies from funders, publishers, and the scientific community have led to requirements that reported structures be promptly deposited in the PDB. As someone who has interacted with the PDB as a consumer, a contributor, a policy-maker, and a funder, I have experienced the power and challenges of trying to optimize such a public resource. The cultural shifts, at the cutting (and often bleeding) edge of open science, were often controversial, but it is hard to argue that they have not both increased the impact of individual determined structures and accelerated scientific progress in many ways. The ever-growing PDB provides researchers with a universe of structures with which to compare their favorite structures. The new structure prediction tools expand this universe further and provide truly compelling evidence of the power of open science. Moreover, these tools bring truth to an old saying in structural biology circles, โ€œThe structure prediction problem has been solved; itโ€™s hiding in the PDB.โ€



Hunting for Detections in Attack Data with Machine Learning

#artificialintelligence

As a (fairly) new member of Splunk's Threat Research team (STRT), I found a unique opportunity to train machine learning models in a more impactful way. I focus on the application of natural language processing and deep learning to build security analytics. I am surrounded by fellow data scientists, blue teamers, reverse engineers, and former SOC analysts with a shared passion and vision to push the state of the art in cyber defense. STRT has collected real-world and simulated attack data that allows me to not only use machine learning to discover attack activity but identify how to transform insights into detections for the benefit of our customers. A recent exercise using machine learning (ML) to hunt threats in Windows audit logs containing traces of post exploit kits illustrates that even small amounts of attack data can create new analytic opportunities.


Part 1: Journey of BERT

#artificialintelligence

BERT is the state-of-the-art model introduced by Jacob Devlin in Google, which changed the course of finding the contextual meaning of words. Eventually, it was adopted by Google in their search engine in 2019 to improvise its searches. Contexts are the word embeddings computed that represent the meaning of the word based on sentences. Earlier word embedding representations like Word2Vec and GloVe represented the word without the contextual meaning. However, with the advancement of the language models from RNN to BERT, the computation to find the contextual embeddings became more efficient and better.


Multi-label Emotion Classification with PyTorch + HuggingFace's Transformers and W&B for Tracking

#artificialintelligence

The GoEmotions dataset contains 58k carefully curated Reddit comments labeled for 27 emotion categories or Neutral. The raw data is included as well as the smaller, simplified version of the dataset with predefined train/val/test splits. After going through a few examples in this dataset on their visualizer, I realized that this is an extremely crucial dataset because it's rare to find sentiment classifier datasets that go beyond 5โ€“6 emotions. But here, we have 27 emotions being assigned, with rare and close enough emotions like disappointment, disapproval, grief, remorse, sadness, etc. Detecting such close enough emotions is often difficult in typical datasets. This made it clear to me that this is an excellent dataset that can be scaled for usage in many applications that involve text analysis.


Deep learning of neural networks

#artificialintelligence

The development of technology has raised humanity to unprecedented heights. The fields of medicine, security, education, and other types of care are at their peak. But that is not all. Artificial intelligence is the next big thing in the world of technology and computer science, but to understand it, it's important to know what it is made of. It is important to know what deep learning is and what an artificial neural network is.


Distributed Deep Learning -- Illustrated

#artificialintelligence

In this article, I will illustrate how distributed deep learning works. I have created animations that should help you get a high-level understanding of distributed deep learning. But let's start with the basics. Graphics processing units (GPUs) are specialized cores that can perform multiple, simultaneous mathematical computations. Deep learning computations can be broken down into a series of matrix multiplications and that is where GPUs excel over CPUs.


GLMs Part III: Deep Neural Networks as Recursive Generalized Linear Models

#artificialintelligence

Generalized Linear Models (GLMs) play a critical role in fields including Statistics, Data Science, Machine Learning, and other computational sciences. Part I of this Series provided a thorough mathematical overview with proofs of common GLMs, both in Canonical and Non-Canonical forms. Part II provided historical and mathematical context of common iterative numerical fitting procedures for GLMs including Newton-Raphson, Fisher Scoring, Iteratively Reweighted Least Squares, and Gradient Descent. In the last of this three-part Series, we explore Neural Networks and their connection with GLMs. In-fact, Neural Networks are nothing more than recursive Canonical GLMs.


Tensorflow and Keras For Neural Networks and Deep Learning - CouponED

#artificialintelligence

It is a practical, hands-on course, i.e. we will spend some time dealing with some of the theoretical concepts related to data science. However, majority of the course will focus on implementing different techniques on real data and interpret the results.. After each video you will learn a new concept or technique which you may apply to your own projects!