<Tr> <Td_colspan="2"> The human beta - 2 adrenergic receptor in complex with the partial inverse agonist carazolol . </Td> </Tr> <Tr> <Th_colspan="2"> Identifiers </Th> </Tr> <Tr> <Th> Symbol </Th> <Td> 7tm_1 </Td> </Tr> <Tr> <Th> Pfam </Th> <Td> PF00001 </Td> </Tr>

Where are g protein coupled receptors located in the cell