Crystal Structures of the ATPase Domains of Four Human Hsp70 Isoforms: HSPA1L/Hsp70-hom, HSPA2/Hsp70-2, HSPA6/Hsp70B', and HSPA5/BiP/GRP78

The 70-kDa heat shock proteins (Hsp70) are chaperones with central roles in processes that involve polypeptide remodeling events. Hsp70 proteins consist of two major functional domains: an N-terminal nucleotide binding domain (NBD) with ATPase activity, and a C-terminal substrate binding domain (SBD). We present the first crystal structures of four human Hsp70 isoforms, those of the NBDs of HSPA1L, HSPA2, HSPA5 and HSPA6. As previously with Hsp70 family members, all four proteins crystallized in a closed cleft conformation, although a slight cleft opening through rotation of subdomain IIB was observed for the HSPA5-ADP complex. The structures presented here support the view that the NBDs of human Hsp70 function by conserved mechanisms and contribute little to isoform specificity, which instead is brought about by the SBDs and by accessory proteins.This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1

Structure-based functional inference of hypothetical proteins from Mycoplasma hyopneumoniae

Enzootic pneumonia caused by Mycoplasma hyopneumoniae is a major constraint to efficient pork production throughout the world. This pathogen has a small genome with 716 coding sequences, of which 418 are homologous to proteins with known functions. However, almost 42% of the 716 coding sequences are annotated as hypothetical proteins. Alternative methodologies such as threading and comparative modeling can be used to predict structures and functions of such hypothetical proteins. Often, these alternative methods can answer questions about the properties of a model system faster than experiments. In this study, we predicted the structures of seven proteins annotated as hypothetical in M. hyopneumoniae, using the structure-based approaches mentioned above. Three proteins were predicted to be involved in metabolic processes, two proteins in transcription and two proteins where no function could be assigned. However, the modeled structures of the last two proteins suggested experimental designs to identify their functions. Our findings are important in diminishing the gap between the lack of annotation of important metabolic pathways and the great number of hypothetical proteins in the M. hyopneumoniae genome

A Forward-Genetic Screen and Dynamic Analysis of Lambda Phage Host-Dependencies Reveals an Extensive Interaction Network and a New Anti-Viral Strategy

Latently infecting viruses are an important class of virus that plays a key role in viral evolution and human health. Here we report a genome-scale forward-genetics screen for host-dependencies of the latently-infecting bacteriophage lambda. This screen identified 57 Escherichia coli (E. coli) genes—over half of which have not been previously associated with infection—that when knocked out inhibited lambda phage's ability to replicate. Our results demonstrate a highly integrated network between lambda and its host, in striking contrast to the results from a similar screen using the lytic-only infecting T7 virus. We then measured the growth of E. coli under normal and infected conditions, using wild-type and knockout strains deficient in one of the identified host genes, and found that genes from the same pathway often exhibited similar growth dynamics. This observation, combined with further computational and experimental analysis, led us to identify a previously unannotated gene, yneJ, as a novel regulator of lamB gene expression. A surprising result of this work was the identification of two highly conserved pathways involved in tRNA thiolation—one pathway is required for efficient lambda replication, while the other has anti-viral properties inhibiting lambda replication. Based on our data, it appears that 2-thiouridine modification of tRNAGlu, tRNAGln, and tRNALys is particularly important for the efficient production of infectious lambda phage particles

Odwadniacze termodynamiczne stosowane w przemyśle drzewnym

"Thermodynamic steam traps used in the wood industry". We use three big families of demountable steam traps in the wood industry - mechanical steam traps with closed or open float, thermodynamic and thermostatic steam traps. In addition to these families dismountable steam traps have appeared on the market. They are produced in thermostatic and mechanical float versions. For heating devices, in which we have to deal with heat load, changing in the wide broad, which may lead to suspension of the condensate, we use pumping steam traps combining the features of float steam traps and portion pump. Using appropriate steam trap selection criteria, we are able to eliminate energy loss due to steam loss."Odwadniacze termodynamiczne stosowane w przemyśle drzewnym". W przemyśle drzewnym stosujemy trzy duże rodziny odwadniaczy rozbieralnych. Zaliczamy do nich odwadniacze mechaniczne z pływakiem zamkniętym lub otwartym, odwadniacze termodynamiczne i termostatyczne. Poza wymienionymi rodzinami pojawiły się na rynku odwadniacze nierozbieralne. Produkowane są one w wersji termostatycznej oraz mechanicznej pływakowej. Do urządzeń grzewczych, w których mamy do czynienia z obciążeniem cieplnym zmieniającym się w szerokim zakresie, mogącym prowadzić do zawieszania się kondensatu stosujemy odwadniacze pompujące, łączące cechy odwadniaczy pływakowych i pompy porcjowej. Stosując właściwe kryteria doboru odwadniaczy, jesteśmy w stanie straty energii spowodowane ubytkami pary wodnej praktycznie wyeliminować