Through various pathways of cell death, degradation, and regulated extrusion, partial or complete genomes of various origins (e.g., host cells, fetal cells, and infiltrating viruses and microbes) are continuously shed into human body fluids in the form of segmented cell-free DNA (cfDNA) molecules. While the genetic complexity of total cfDNA is vast, the development of progressively efficient extraction, high-throughput sequencing, characterization via bioinformatics procedures, and detection have resulted in increasingly accurate partitioning and profiling of cfDNA subtypes. Not surprisingly, cfDNA analysis is emerging as a powerful clinical tool in many branches of medicine. In addition, the low invasiveness of longitudinal cfDNA sampling provides unprecedented access to study temporal genomic changes in a variety of contexts. However, the genetic diversity of cfDNA is also a great source of ambiguity and poses significant experimental and analytical challenges. For example, the cfDNA population in the bloodstream is heterogeneous and also fluctuates dynamically, differs between individuals, and exhibits numerous overlapping features despite often originating from different sources and processes. Therefore, a deeper understanding of the determining variables that impact the properties of cfDNA is crucial, however, thus far, is largely lacking. In this work we review recent and historical research on active vs. passive release mechanisms and estimate the significance and extent of their contribution to the composition of cfDNA.

The monkeypox virus (MPX) belongs to the Orthopoxvirus genus of the Poxviridae family, is endemic in parts of Africa and causes a disease in humans similar to smallpox. The most recent outbreak of MPX is already affecting 110 countries, with 86,956 confirmed cases since May 2022 and has consequently become a focus of interest. In particular, a molecular understanding of the virus is essential to study infection processes and pathogen-host interactions, predict tropism changes, or guide drug development and drug discovery as well as vaccine development or vaccine adaptation at a very early stage. Herein, we present a study of the structural proteome of the currently circulating MPX: Our consensus analysis of 3,713 genome sequences sampled within a year after the outbreak revealed 10,580 characteristic candidate open reading frames (ORFs). A search in the non-redundant protein database reduced the number of suspected ORFs to 1,079, of which 210 are representative proteins in typical MPX reference genomes. This should serve as a collection of putative proteins within the currently spreading MPX, a compound of information that could support timely drug discovery, mutational analyses, and vaccine development. We, herein, present the so far most comprehensive structural proteome by providing atomistic 3D models of 210 proteins, generated with three state-of-the-art structure prediction methods, including a mutational analysis of the proteome, with a particular focus on the drug-binding sites of tecovirimat and brincidofovir. IMPORTANCE: The 2022 outbreak of the monkeypox virus already involves, by April 2023, 110 countries with 86,956 confirmed cases and 119 deaths. Understanding an emerging disease on a molecular level is essential to study infection processes and eventually guide drug discovery at an early stage. To support this, we provide the so far most comprehensive structural proteome of the monkeypox virus, which includes 210 structural models, each computed with three state-of-the-art structure prediction methods. Instead of building on a single-genome sequence, we generated our models from a consensus of 3,713 high-quality genome sequences sampled from patients within 1 year of the outbreak. Therefore, we present an average structural proteome of the currently isolated viruses, including mutational analyses with a special focus on drug-binding sites. Continuing dynamic mutation monitoring within the structural proteome presented here is essential to timely predict possible physiological changes in the evolving virus.