In the second half, econometric analysis (regression testing) is used to isolate the key factors affecting HAMP modification performance and to compare the performance of loans modified through HAMP with other similarly delinquent loans. The innovation in this study comes from the merging of HAMP program data with a commercial loan performance database, which allows HAMP-modified loans to be co...

HAMP domains are signal relay modules in >26,000 receptors of bacteria, eukaryotes, and archaea that mediate processes involved in chemotaxis, pathogenesis, and biofilm formation. We identify two HAMP conformations distinguished by a four- to two-helix packing transition at the C-termini that send opposing signals in bacterial chemoreceptors. Crystal structures of signal-locked mutants establis...

HAMP domains mediate input-output transactions in many bacterial signalling proteins. To clarify the mechanistic logic of HAMP signalling, we constructed Tsr-HAMP deletion derivatives and characterized their steady-state signal outputs and sensory adaptation properties with flagellar rotation and receptor methylation assays. Tsr molecules lacking the entire HAMP domain or just the HAMP-AS2 heli...

Aer, the Escherichia coli aerotaxis receptor, faces the cytoplasm, where the PAS (Per-ARNT-Sim)-flavin adenine dinucleotide (FAD) domain senses redox changes in the electron transport system or cytoplasm. PAS-FAD interacts with a HAMP (histidine kinase, adenylyl cyclase, methyl-accepting protein, and phosphatase) domain to form an input-output module for Aer signaling. In this study, the struct...

HAMP domains are signal transduction domains typically located between the membrane anchor and cytoplasmic signaling domain of the proteins in which they occur. The prototypical structure consists of two helical amphipathic sequences (AS-1 and AS-2) connected by a region of undetermined structure. The Escherichia coli aerotaxis receptor, Aer, has a HAMP domain and a PAS domain with a flavin ade...

The HAMP domain is a linker region in prokaryotic sensor proteins and relays input signals to the transmitter domain and vice versa. Functional as a dimer, the structure of HAMP shows a parallel coiled-coil motif comprising four helices. To date, it is unclear how HAMP can relay signals from one domain to another, although several models exist. In this work, we use molecular simulation to test ...

In this paper I develop and estimate a dynamic model of the household decision to default on a mortgage using data from the Homeowners Affordability Modification Program (HAMP), which reduces delinquent homeowner housing payments to 31 percent of income. I find that HAMP has prevented 550,000 defaults as of June 2013 relative to a scenario where HAMP does not exist, at a cost-per-default preven...

Inappropriately low expression of the key iron regulator hepcidin (HAMP) causes iron overload in untransfused patients affected by β-thalassemia intermedia and Hamp modulation provides improvement of the thalassemic phenotype of the Hbb(th3/+) mouse. HAMP expression is activated by iron through the bone morphogenetic protein (BMP)-son of mothers against decapentaplegic signaling pathway and inh...

ATOH8 has previously been shown to be an iron-regulated transcription factor, however its role in iron metabolism is not known. ATOH8 expression in HEK293 cells resulted in increased endogenous HAMP mRNA levels as well as HAMP promoter activity. Mutation of the E-box or SMAD response elements within the HAMP promoter significantly reduced the effects of ATOH8, indicating that ATOH8 activates HA...

Inappropriately low expression of the key iron regulator hepcidin (HAMP) causes iron overload in untransfused patients affected by -thalassemia intermedia and Hamp modulation provides improvement of the thalassemic phenotype of the Hbbth3/ mouse. HAMP expression is activated by iron through the bone morphogenetic protein (BMP)–son of mothers against decapentaplegic signaling pathway and inhibit...