title: Transport of gamma-butyrobetaine in an Agrobacterium species isolated from soil.
abstract: An Agrobacterium sp. isolated from soil by selective growth on gamma-butyrobetaine (gamma-trimethylaminobutyrate) as the sole source of both carbon and nitrogen has been shown to possess an inducible transport system for this growth substrate. This transport system has a Kt of 0.5 microM and a maximal velocity of 3.8 nmol/min per mg (dry weight). The influx of gamma-butyrobetaine is optimal at pH 8.5 and operates against a concentration gradient. The transport system shows a high specificity for trimethylamine carboxylic acid molecules of defined chain length. gamma-Butyrobetaine uptake was significantly reduced in osmotically shocked cells and a gamma-butyrobetaine binding activity was detected in the crude shock fluid. This suggests a transport mechanism involving a periplasmic gamma-butyrobetaine binding protein.
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D001622:Betaine / Q000031:analogs & derivatives* / Q000378:metabolism; D001692:Biological Transport; D002331:Carnitine; D002352:Carrier Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009997:Osmotic Pressure; D012231:Rhizobium / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D001622:Betaine; C002889:gamma-butyrobetaine; D002331:Carnitine