Antenatal anti-D prophylaxis

Encapsulation mechanisms and structural studies of GRM2 bacterial microcompartment particles

Bacterial microcompartments (BMCs) are prokaryotic organelles consisting of a protein shell and an encapsulated enzymatic core. BMCs are involved in several biochemical processes, such as choline, glycerol and ethanolamine degradation and carbon fixation. Since non-native enzymes can also be encapsulated in BMCs, an improved understanding of BMC shell assembly and encapsulation processes could be useful for synthetic biology applications. Here we report the isolation and recombinant expression of BMC structural genes from the Klebsiella pneumoniae GRM2 locus, the investigation of mechanisms behind encapsulation of the core enzymes, and the characterization of shell particles by cryo-EM. We conclude that the enzymatic core is encapsulated in a hierarchical manner and that the CutC choline lyase may play a secondary role as an adaptor protein. We also present a cryo-EM structure of a pT = 4 quasi-symmetric icosahedral shell particle at 3.3 Å resolution, and demonstrate variability among the minor shell forms.

The Du phenotype, serology, and clinical relevance

In this article, the authors examine the nature of the Du phenomenon through a comprehensive historical review beginning with the initial description of the Du factor in the 1940s. Pertinent developments in serologic testing methods and genetic concepts are described. Evidence of the importance of the Du factor in transfusion and hemolytic disease of the newborn is also presented. Selected articles on the frequency of Du in Caucasian and Negro populations are cited. Finally, the authors review current theoretical concepts concerning the nature of the Du factor, its importance in current transfusion practice and maternal Rh immune globulin administration, and the use of microscopic Du testing as a screening procedure for fetomaternal hemorrhage.