Cellular Electron Cryotomography: Toward Structural Biology In Situ

10.1146/annurev-biochem-061516-044741

2017-06-27

Electron cryotomography (ECT) provides three-dimensional views of macromolecular complexes inside cells in a native frozen–hydrated state. Over the last two decades, ECT has revealed the ultrastructure of cells in unprecedented detail. It has also allowed us ...

Microbial Rhodopsins: Diversity, Mechanisms, and Optogenetic Applications

10.1146/annurev-biochem-101910-144233

2017-06-27

Microbial rhodopsins are a family of photoactive retinylidene proteins widespread throughout the microbial world. They are notable for their diversity of function, using variations of a shared seven-transmembrane helix design and similar photochemical reactio...

Teaching Old Dyes New Tricks: Biological Probes Built from Fluoresceins and Rhodamines

10.1146/annurev-biochem-061516-044839

2017-06-27

Small-molecule fluorophores, such as fluorescein and rhodamine derivatives, are critical tools in modern biochemical and biological research. The field of chemical dyes is old; colored molecules were first discovered in the 1800s, and the fluorescein and rhod...

Extracellular Heme Uptake and the Challenge of Bacterial Cell Membranes

10.1146/annurev-biochem-060815-014214

2017-06-27

Iron is essential for the survival of most bacteria but presents a significant challenge given its limited bioavailability. Furthermore, the toxicity of iron combined with the need to maintain physiological iron levels within a narrow concentration range requ...

Redox-Based Regulation of Bacterial Development and Behavior

10.1146/annurev-biochem-061516-044453

2017-06-27

Severe changes in the environmental redox potential, and resulting alterations in the oxidation states of intracellular metabolites and enzymes, have historically been considered negative stressors, requiring responses that are strictly defensive. However, re...

Multiple Functions and Regulation of Mammalian Peroxiredoxins

10.1146/annurev-biochem-060815-014431

2017-06-27

Peroxiredoxins (Prxs) constitute a major family of peroxidases, with mammalian cells expressing six Prx isoforms (PrxI to PrxVI). Cells produce hydrogen peroxide (H2O2) at various intracellular locations where it can serve as a signaling molecule. Given that ...

Oxidative Stress

10.1146/annurev-biochem-061516-045037

2017-06-27

Oxidative stress is two sided: Whereas excessive oxidant challenge causes damage to biomolecules, maintenance of a physiological level of oxidant challenge, termed oxidative eustress, is essential for governing life processes through redox signaling. Recent i...

Mitochondrial Machineries for Protein Import and Assembly

10.1146/annurev-biochem-060815-014352

2017-06-27

Mitochondria are essential organelles with numerous functions in cellular metabolism and homeostasis. Most of the >1,000 different mitochondrial proteins are synthesized as precursors in the cytosol and are imported into mitochondria by five transport pathway...

Endoplasmic Reticulum–Plasma Membrane Contact Sites

10.1146/annurev-biochem-061516-044932

2017-06-27

The endoplasmic reticulum (ER) has a broad localization throughout the cell and forms direct physical contacts with all other classes of membranous organelles, including the plasma membrane (PM). A number of protein tethers that mediate these contacts have be...

The Evolution of Organellar Coat Complexes and Organization of the Eukaryotic Cell

10.1146/annurev-biochem-061516-044643

2017-06-27

Eukaryotic cells possess a remarkably diverse range of organelles that provide compartmentalization for distinct cellular functions and are likely responsible for the remarkable success of these organisms. The origins and subsequent elaboration of these compa...