Briquetage And Brine: Living And Working At The Classic Maya Salt Works Of Ek Way Nal, Belize

Systematic flotation survey and spatial analysis of artifacts at the submerged salt work of Ek Way Nal reveal evidence of a residence, salt kitchens, and additional activities. Ek Way Nal is one of 110 salt works associated with a Late to Terminal Classic (A.D. 600-900) salt industry known as the Paynes Creek Salt Works. Wooden posts that form the walls of 10 buildings are remarkably preserved in a peat bog below the sea floor providing an opportunity to examine surface artifacts in relation to buildings. Numerous salt kitchens have been located at the Paynes Creek Salt Works by evidence of abundant briquetage - pottery associated with boiling brine over fires to make salt. As one of the largest salt works with 10 buildings, there is an opportunity to examine variability in building use. Systematic flotation survey over the site and flagging and mapping individual artifacts and posts provide evidence that the Ek Way Nal salt makers had a residence near the salt kitchens, along with evidence of salting fish for subsistence or surplus household production. The results are compared with ethnographic evidence from Sacapulas and other salt work

Household salt production by the Late Classic Maya: underwater excavations at Ta\u27ab Nuk Na

Salt is an essential commodity; archaeological remains around the world attest to the importance of its production, exchange and consumption. Often located in coastal locations, many production sites were submerged by rising seas, including the Paynes Creek Salt Works on the southern Belize coast. Survey and excavation of these sites has identified ‘kitchens’ for brine boiling, as well as Terminal Classic residential structures at Ek Way Nal. The authors report the discovery of an earlier residential building alongside salt kitchens at the nearby site of Ta\u27ab Nuk Na. This finding indicates that surplus household production began during the Late Classic, when demand for salt from inland cities was at its peak

Collagen-Like Proteins in Pathogenic E. coli Strains

The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages