In general, sugar porters function by proton-coupled symport or facilitative transport modes.
And standing as a solitary sentinel over all this was an ancient porter, "whose function", admitted Montaigne, "is not so much to defend his door as to offer it with more grace and decorum", making an attack on it "a cowardly and treacherous business... it is not shut to anyone that knocks".
As substrate transport and power generation are two functions physically separated (in the porter and TM domains, respectively), reliable communication and energy coupling between the two corresponding layers are essential for ensuring proper energy-transduction efficiency and thus high transport rate.
We excluded observations if they occurred before 1970, if climbers did not travel above base camp, or if climbers functioned as a high altitude porter.
New fighting, new recruitment Part of South Sudan's 30-year legacy of conflict has been the recruitment of children into armed groups – both those forced to fight among the ranks and those made to fulfil support functions like porters, cooks or radio operators.
"Clearly there is unfairness in the pay system and that hurts our members, who are mainly technicians, porters and cleaning staff without whom universities would not function.
Sugar porters are found in bacteria, archaea and eukarya and function by uniport or proton-coupled symport modes of transport [ 2].
Interestingly, each repeat is flanked by a single transmembrane helix that seems to function as a coupling element with the periplasmic porter domain.
This occurs because of the prevention of the sodium ion efflux, either by the actions of a sodium anti-porter or a sodium/potassium ATPase exchanger, which requires ATP for transporter function.
The children, in some cases as young as 10, were recruited and used as combatants, or in support functions such as porters and cooks.
