Expectation-maximization for structure determination directly from cryo-EM micrographs

Fuente: arXiv
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Autori principali: Kreymer, Shay, Singer, Amit, Bendory, Tamir
Natura: Preprint
Pubblicazione: 2023
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author Kreymer, Shay
Singer, Amit
Bendory, Tamir
author_facet Kreymer, Shay
Singer, Amit
Bendory, Tamir
contents A single-particle cryo-electron microscopy (cryo-EM) measurement, called a micrograph, consists of multiple two-dimensional tomographic projections of a three-dimensional (3-D) molecular structure at unknown locations, taken under unknown viewing directions. All existing cryo-EM algorithmic pipelines first locate and extract the projection images, and then reconstruct the structure from the extracted images. However, if the molecular structure is small, the signal-to-noise ratio (SNR) of the data is very low, making it challenging to accurately detect projection images within the micrograph. Consequently, all standard techniques fail in low-SNR regimes. To recover molecular structures from measurements of low SNR, and in particular small molecular structures, we devise an approximate expectation-maximization algorithm to estimate the 3-D structure directly from the micrograph, bypassing the need to locate the projection images. We corroborate our computational scheme with numerical experiments and present successful structure recoveries from simulated noisy measurements.
format Preprint
id arxiv_https___arxiv_org_abs_2303_02157
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Expectation-maximization for structure determination directly from cryo-EM micrographs
Kreymer, Shay
Singer, Amit
Bendory, Tamir
Image and Video Processing
Signal Processing
Quantitative Methods
A single-particle cryo-electron microscopy (cryo-EM) measurement, called a micrograph, consists of multiple two-dimensional tomographic projections of a three-dimensional (3-D) molecular structure at unknown locations, taken under unknown viewing directions. All existing cryo-EM algorithmic pipelines first locate and extract the projection images, and then reconstruct the structure from the extracted images. However, if the molecular structure is small, the signal-to-noise ratio (SNR) of the data is very low, making it challenging to accurately detect projection images within the micrograph. Consequently, all standard techniques fail in low-SNR regimes. To recover molecular structures from measurements of low SNR, and in particular small molecular structures, we devise an approximate expectation-maximization algorithm to estimate the 3-D structure directly from the micrograph, bypassing the need to locate the projection images. We corroborate our computational scheme with numerical experiments and present successful structure recoveries from simulated noisy measurements.
title Expectation-maximization for structure determination directly from cryo-EM micrographs
topic Image and Video Processing
Signal Processing
Quantitative Methods
url https://arxiv.org/abs/2303.02157