The gate church dedicated to St. Sergius of Radonezh is part of the ensemble of the Holy Trinity Stepan-Makhri Stavropegial Convent. This two-story brick building was constructed in 1791 with funds from Metropolitan Platon and is located in the eastern part of the monastery walls.

The church is strictly oriented to the cardinal directions. Its walls are made of large bricks on a lime mortar, with joints smoothed and facades whitewashed. The roofs are made of unpainted copper. The building has a T-shaped form, with entrance gates along the main axis. On the second floor, in the eastern projection, there is a large apse. Previously, a side staircase led upstairs, which is now lost. The square part is covered with a vaulted ceiling, while the apse and chapels have flat ceilings on wooden beams.

The central part of the building is topped with an onion dome on a thin low neck, and the decor is made of brick. The upper tier of the square is separated by a multi-profile cornice that runs around the entire perimeter of the building, just above the level of the adjoining monastery walls. The lower tier of the eastern wall with the gates is adorned with a pulled rustication and a triangular pediment with a cornice of 'towns'. Tall windows are framed with flat rectangular casings.

Inside, the building is plastered, but monumental painting has been lost. The church is an example of monastic architecture executed in a transitional style from Baroque to Classicism and is one of the first stone constructions of the monastery.

From 2008 to 2014, preservation work was carried out on the building. This included removing plaster from certain areas of the facades, restoring the face of the brickwork, injecting the brickwork, repairing the floor on the first floor and in the passage arch, as well as repairing the walls and ceilings on both floors. Interior work included cleaning the walls, finishing the plastered surface, repairing the staircase, cladding the steps with granite slabs, gilding the cross and dome, and replacing windows and doors with analogs.