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Team:KULeuven/Project/Memory
From 2008.igem.org
Contents |
Memory
BioBricks
Components
BBa_C0052 is the cI repressor from phage 434, edited with an LVA-tag. It is placed under control of BBa_R0053, the phage 22 cII regulated promoter. BBa_C0053 codes for the phage 22 cII repressor molecule and is placed under control of a modified lamdba Prm promoter that is repressed by 434 cI BBa_I12006. A third subdivision consists of the BBa_C0052 cI repressor from phage 434 under control of the OmpF promoter (BBa_R0084). The forth and last subdivision is an antisense LuxI mRNA (encoded by BBa_K145013) under control of the modified lamdba Prm promoter BBa_I12006.
Action
Note that in the schematic picture of the memory, BBa_C0052 is depicted as act and BBa_C0053 as Rep.
When there is no signal from the input device, and there has never been one, no 434 cI repressor is made. This means that there is no repression of BBa_I12006, the modified lamdba Prm promoter. As a consequence of this, BBa_C0053, the phage 22 cII repressor is made, repressing BBa_R0053, the cII p22 regulated promoter. As said, BBa_I12006 is not repressed, and antisense LuxI (BBa_K145013) makes sure that no LuxI is transcribed, thereby preventing HSL production.
From the moment an input signal emerges, the 434 cI repressor is made, repressing transcription of phage 22 cII repressor. This turns the phage 22 promoter on, resulting in further production of phage 434 cI repressor. Antisense LuxI production ceases, and LuxI begins producing HSL.
From now on, phage 434 cI repressor accumulates and phage 22 cII inhibitor concentrations quickly drop to zero. This is nicely pictured on the modeling page of the memory system.
